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LG G Flex 2 review: tomorrow’s tech, yesterday’s problems

By Michael Fisher February 18, 2015, 7:03 pm

“This might be my next phone.”

That’s how I wrapped up our hands-on coverage of the LG G Flex 2 at CES 2015, and I meant it so hard. It was the tamest quote I could come up with after spending an hour with the curvaceous crimson smartphone, which seemed poised to finally catapult curved construction from obscurity to the mainstream. I’d spent weeks with its predecessor back in 2013, whose principal shortcomings were its oversized footprint and its lackluster display – and it took only minutes with the G Flex 2 to see how well those issues had been addressed.

It took six days of hard use in the real world, though, to see just how many issues remain. The LG G Flex 2 isn’t just a futuristic-looking smartphone; it brings a boatload of never-before-seen technology from the processor to the paint job – and not all of it works as well as it could. As a result, the G Flex 2 definitely won’t be my next phone … until some things get ironed out, anyway. Join us as we suss out the triumphs from the letdowns in our LG G Flex 2 review.

lg g flex 2 review 1

Note: The model we test in this review is the 2GB LG-F510S for South Korea, the only market with widespread G Flex 2 availability at press time. As a result, network-dependent factors such as radio performance, audio quality, and battery life are subject to a fair degree of error. Once the G Flex 2 becomes available in the US, we’ll review the stateside version and follow up on these issues.

Video Review · Specs & Hardware · Software · Camera · Test Notes

 Pros/Cons · Pricing/Availability · Conclusion · Scored For Me

LG G Flex 2 Review Video


Specs & Hardware

lg g flex review 2
lg g flex review rear key

As flamboyant as the G Flex 2 is from a design standpoint, its spec sheet includes some commendable restraint on LG’s part. You won’t find a quad-HD display here, nor the new Gorilla Glass 4 display protection included on devices like Samsung’s Galaxy Note 4. Instead, LG makes do with a custom refinement of third-generation Gorilla Glass, put through a proprietary thermal/chemical treatment that LG claims renders it 20 percent stronger than on other devices. And rather than going for a senselessly high pixel count for the display, LG has instead focused on solving the mottling and image-retention problems of the last round of P-OLED screens.

The G Flex 2 chassis shows markedly less restraint. While the Platinum Silver edition is certainly more reserved than the Flamenco Red of our review device, both versions bear a characteristic not found anywhere else on the market: a subtle curve running from top to bottom. The curve’s radius varies at different points on the device: on the screen it’s 700mm; on the rear cover it’s 650mm; and it narrows to a tight 400mm along the sides for maximum grip-ability. Though these are similar measurements to the curves on the first G Flex, they’re more subtle on the G Flex 2 because the device is smaller. The result is a phone that looks dramatically bent from some angles, and almost conventional from others.

lg g flex review side

In the hand, all those curves come together to make the 152g package one of the most comfortable smartphones on the market. It hugs the cheek during voice calls, bringing the microphone slightly closer to the mouth; it conforms to the palm, rendering one-handed use a bit easier; it makes movie-watching and gaming just a tad more immersive; and it brings just enough bend to make it perfect for a back pocket – but not so much as to feel uncomfortable in a front pocket. And if you’re a member of the tight-pants crowd worried about breaking your phone when you sit on it, the G Flex 2 has you covered: true to its name, it flexes when stressed, popping instantly back to its out-of-box shape when the pressure comes off.


The bendy build combines with other LG staples to make the G Flex 2 still more comfortable. The rear-key collective containing the volume rocker and power/standby toggle sits right on the sweet spot for an index finger, and also frees up the sides of the phone for those super-slim bezels. As on the G3, key-travel and feedback is solid and much-improved over the somewhat mushy keys on the first-generation Flex (though we miss the latter’s rear-mounted notification LED). Even the paint job gets a pass because of the added functionality it brings: we’d normally come down pretty hard on the glossy finish, which attracts fingerprints and dust like it’s an old-school CRT screen. But the tactile sacrifice is forgivable here, because the paint job needs to be glossy to make its self-healing technology work: according to LG, the new high-density coating self-repairs minor scuffs and scratches in as little as ten seconds. If that claim seems a little too good to be true, our initial impressions agree: I used a SIM key to scratch some light underlines beneath the LG logo on the phone’s backside. An hour later the scratches were still there, and showed no signs of disappearing. (We’ll put the self-healing coating to a more thorough test in a future video.)


lg g flex review 4

The phone’s high technology isn’t confined to the exterior. Beneath the “spin hairline” finish sit 2GB of LPDDR4 RAM on our demo device, but a 3GB model is also available. You can choose between 16 or 32GB of eMMC storage; choosing the latter will net you only about 21GB on first boot though, thanks to the truly absurd amount of bloatware imposed by operator SK Telecom. Thankfully, the G Flex 2’s back cover pops off to reveal a microSD expansion slot which LG says is good for memory cards up to 2TB in size – a claim we’ll put to the test once 2TB cards actually hit the market.

The real star of the smartphone is one of the world’s newest processors: the 64-bit, octa-core Snapdragon 810. This is the next generation of Qualcomm silicon, and represents a break from its traditional Krait-powered roots. Instead of the familiar quad-core design, the 810 uses a big.LITTLE implementation similar to the Exynos processors we’ve seen on some Samsung smartphones: four Cortex A57 “high power” cores and four “low power” Cortex A53s, mated to an Adreno 430 for graphics processing. AnandTech has a great write-up about the Snapdragon 810’s performance, coming away with largely positive conclusions after testing the SoC on Qualcomm’s large reference hardware. But like fate, miniaturization is a cruel mistress. Within the confines of the 9.4mm-thick G Flex 2, the processor doesn’t have as much space to dissipate heat. The result is some pretty aggressive thermal throttling, which makes the phone’s software run very slowly at times. Here’s where things start to get rough.



LG G Flex 2 review UI 1

As I write this review, I’m listening to my traditional writing playlist on Spotify, which is streaming from the G Flex 2 to a pair of Sennheiser MM100 Bluetooth headphones. Controlling the volume is easy –the rear-mounted control collective is very handy if you place your phone face-down on a table– but changing tracks requires me to wake the phone. Doing that is easy too (double-tap-to-wake and Knock Code are both very convenient interface touches), but once I get past the lock screen, the waiting begins. Three out of five times, I have to wait for the Android home screen to redraw itself before I can do anything – a procedure that takes anywhere from three to ten seconds, depending on the phone’s mood. If I try to bypass the home screen, for example by pulling down the notification shade to get at the Spotify controls there, it only makes the lag worse.

It’s not just Spotify, either. Running other apps like Google Maps driving navigation or TuneIn Radio also takes a toll on the system’s responsiveness. Even without imposing such a background processing load, the G Flex 2 is wildly inconsistent: sometimes the interface flies under a fingertip, and other times it bogs down so badly that I feel as though I’m using a Moto E again. The problem seems to get worse with uptime –the longer the G Flex 2 goes between reboots, the slower its performance gets– and it’s at its worst after a prolonged period of dormancy. Wake the phone up after it’s been in standby for a few hours, and expect to wait a good long while for the UI to catch up to your inputs.

Often, this performance lag goes hand-in-hand with a big dive in battery life. At 50 percent screen brightness with no other apps running in the task manager, I once watched the G Flex 2 lose 20 percent battery in less than an hour, when I was doing nothing more involved than reading the mobile version of a newspaper with almost no graphics. The phone even bogged down when running Asphalt 8, a graphically-intense game at which it should excel. The performance smoothed out once I’d closed all other running apps, but that’s not a step I typically need to take on a flagship smartphone – least of all one that’s already on store shelves in South Korea.

To LG’s credit, the company acknowledges it has some tweaking to do with regard to the G Flex 2’s performance. When I reached out for comment, LG responded with the following statement:

The devices sampled are representative of final industrial design and user experience but are continuing to undergo additional optimizations to enhance benchmark performance. We expect our upcoming software releases to provide further improvements in this area. We remain confident that the G Flex 2 will deliver great experiences to our customers with a tremendous blend of multimedia, performance and industry-leading design.

While the issues I’m having have less to do with benchmark scores than day-to-day responsiveness, it’s nice to see LG taking the performance problems seriously – and this seems as good a place as any to remind you that we will be re-testing a US version of the LG G Flex 2 when it lands in North America, so hopefully some of these bugs will have been worked out by then. (It’s also probable the 3GB version of the device offers a better multitasking experience; we’ll follow up on that if we’re given the opportunity to test one.)


Visually, the software experience is almost identical to that of the LG G3, which we largely praised in last summer’s review. Standouts include the excellent keyboard with its persistent number row, adjustable height, and fine cursor positioning; the ample multitasking options for making the most of the big 5.5-inch display; and the clean, reserved look of the interface as a whole. While there’s no real reason to use LG’s Smart Notice cards over the (much-smarter) Google Now, using the two in concert is nice: Google Now will let you know how far away the next train is, while Smart Notice reminds you to bundle up before you head out because you’re about to get more snow. Just in case you forget about the fluffy stuff outside, the lock screen gives you a very pretty current-weather animation every time you wake the phone up. LG Health makes tracking your steps and your jogging route simpler than some other built-in fitness solutions. And you can fine tune almost any aspect of the interface you want: drop a toggle in the home-key row so you can more easily trigger the notification shade, then edit the shade to add or remove everything from connectivity controls to volume and brightness sliders. Check out our earlier video review of the LG G3 for more on the LG UI:



lg g flex review camera

Also familiar from the G3: the camera. LG effectively lifted the G3’s entire optics package for the G Flex 2, including the 13MP sensor, laser-autofocus module, and the “OIS+” optical image stabilization rig (the omission of which was one of the biggest compromises on the first G Flex). While there’s no hardware shutter button, jumping into the camera to snap a shot is as easy as holding the volume-down key for a second. Once the streamlined viewfinder app comes up, focus times are indeed very fast thanks to that laser.

The photos the G Flex 2 produced range in quality depending on lighting. While the autofocus is fast, it’s not immune to drifting: a few of the outdoor pictures I took don’t seem to have a defined focal point (possibly because blowing snow confused the camera). Most outside shots are nice enough though, with the kind of crisp detail and contrast we’ve come to expect from high-end smartphone cameras. Saturation is a little on the low side, though – and that problem gets much worse indoors. The fire extinguisher pictured in the sample below is much more red in real life – same with the red LED on the handheld communicator, which is so washed out as to almost look white. There’s also lots of digital noise in almost every photo, which becomes especially pronounced in medium-to-low light. Most of our sample shots were taken at 10MP, but even amping it up to the 13MP maximum, the strange oil-paint look refuses to go away.


LG makes much more noise about the 2.1MP front-facing camera in its promotional materials for the G Flex 2. Shooting selfies with a fist pump feels just as weird as it sounds, but it works very well (and it’s better than shouting “kimchi!” at your phone, though you have that option as well). It’s also easier to immediately review your photo after snapping the shutter; you just bring the phone down to chest level and it’ll automatically jump into the Gallery so you can see how awesome you look. The pictures themselves suffer from the same processing distortion as the main shots and they’re obviously much lower in resolution, but they’re certainly serviceable as far as selfies go, with a wide frame to fit all your buddies and a beauty-face slider to tame your acne or overgrown facial hair or whatever.

As is often the case, video performance falls right in line with the still shots. The brighter the light, the better the scene – and the more flying snow, the more the focus intermittently drifts. On the plus side, low-light capture is actually pretty good. The benefits of optical stabilization are also much more pronounced in video mode, and UHD recording is available to those with a need for maximum sharpness (though the below sample is confined to 1080p).


Test Notes

lg g flex 2 review test notes

As mentioned above, our G Flex 2 review period spanned six days of testing in the Greater Boston area (as of press time), and we’ve spent more of that time evaluating the phone’s day-to-day performance than putting it under the benchmark microscope. Nevertheless, as one of the first commercial devices with a Snapdragon 810 processor we know people will be interested in the results of such testing, so we’ve included a few figures in the screenshots below. Benchmarking the G Flex 2 put its thermal problem front and center: the device heats up very quickly under any kind of processing load, activating the throttling that likely contributes to the responsiveness issues discussed in Software above.

lg g flex heat

Get the phone hot enough and you’ll notice that you can no longer take advantage of the full range of brightness on its P-OLED display. What we thought to be a pixel-density/backlight problem on the LG G3 turns out instead to be aggressive thermal management on the part of LG’s software: the G Flex 2 will force the brightness slider lower as the device temperature rises, making daylight visibility suffer on very sunny days. On the flip side, the brightness slider has almost no effect on the lower third of its track, meaning the display can’t get as dim as the newer AMOLED screens on Motorola and Samsung devices. Bedtime readers, get ready to wake your significant others.

lg g flex 2 battery

If you’re thinking all this heating talk has to have an impact on battery life, you’re right. The original G Flex was an endurance champion with its massive 3500 mAh battery, our in-house device easily offering 6+ hours of screen-on time per charge even a year after its release. By contrast, the new G Flex 2 can make it through the day, but just barely: in nearly a week of testing, we’ve yet to hit 4 hours of screen-on time on a single charge (even when we give up fancy Bluetooth perks like music streaming and Android Wear). Considering the display is “only” full HD, this phone’s 3000 mAh battery should be capable of much more.

Testing the G Flex 2 on T-Mobile US over the course of six days in the Greater Boston area, I found voice quality on-par with the competition, and also got no complaints from the other side about my own sound quality. Again, the curved construction makes talking on the G Flex 2 more comfortable, more natural to we old-schoolers who grew up with “banana phones” in our households. The speakerphone is unfortunately hidden away around back and not as loud as some I’ve tested, but it’s enough for the occasional call, game, or YouTube video. If you’re the more private sort or just want to be courteous to your fellow train riders, the included QuadBeat 2 earbuds offer pretty nice sound for an in-box earset.



+ Beautiful design with unique form factor
+ Comfortable to use in all operating modes
+ Improves on original G Flex in almost every respect
+ Potentially powerful hardware


 Significant software lag
 Underwhelming battery life
 Inconsistent performance throughout


Pricing and Availability

The LG G Flex 2 is currently only broadly available in its native South Korea, with preorders open in Hong Kong and Singapore. US availability is slated for later this year on AT&T, Sprint, and US Cellular, with pricing and exact rollout dates to be determined. If that sounds familiar, it should; the first G Flex hit the market in almost exactly the same staggered fashion. The G Flex 2 price is currently set at 800,000 KRW, which translates to $721 USD for those who’d rather import an out-of-market model than wait for the US release.



lg g flex review 9

In case it’s not obvious by this point, I’m not one of those people. While some phones are worth swallowing high import prices in order to snag them before their stateside launch, the G Flex 2 isn’t (yet) one of them.

That’s not because it’s is a bad device. For one thing, it utterly dominates as a showboat: no other smartphone combines great looks with a comfortable build and innovative materials like this. Especially in Flamenco Red, it’s a genuinely drool-worthy piece of kit. And as a sequel to the original, the G Flex 2 is often brilliant. It’s smaller, svelter, and just as futuristic while simultaneously more accessible to the mainstream. On paper, the G Flex 2 is the perfect “flagship companion” for LG: a mid-cycle premium product meant to augment the primary flagship line (think Galaxy Note vs Galaxy S).

But in the real world, the G Flex 2 is handicapped by one of its biggest differentiators. The stormy relationship between the Snapdragon 810, Android Lollipop and LG’s custom interface makes for a very inconsistent software experience – one that gets more frustrating the longer you use it. Once LG corrects these issues, via its promised software updates or hardware revisions, the G Flex 2 might live up to the potential of its impressive specs and futuristic design. For now, it’s more valuable as yet another reminder that specs aren’t everything.


Scored For Me

g flex 2 sfm



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