The iPhone 4 and the HTC Thunderbolt are very different devices. To start things off, they’re priced differently. For $199, you can get a 16GB iPhone 4 on AT&T with a two year contract, or you can opt for the 32GB model for $299. On Verizon, the Thunderbolt will run you $249 with 32GB of data, making it a better value when you compare storage capacity alone. For data, AT&T has the 2GB data plan for $25 per month, while on Verizon, $30 per month on your bill will get you unlimited data. In our judgement, the Thunderbolt is an overall better value.
In terms of hardware, the Thunderbolt also comes out a winner, with more RAM and a processor that seems to provide better responsiveness in day-to-day operation. In terms of imaging, the rear camera 5MP camera on the iPhone 4 takes better photos and videos than the Thunderbolt, but if you’re interested in video chat, the front-facing camera on the Thunderbolt seems to be a bit better.
Also, if you’re looking for the best screen possible, you can’t beat the iPhone 4 Retina display, which provides an extremely high pixel density, making text and images clear and very crisp. The screen on the Thunderbolt gives you more room to work with, thanks to the large 4.3″ size, and is also no slouch in terms of clarity, but isn’t as good as the iPhone.
In our tests of the web browser and YouTube app, we found the Thunderbolt to be faster. That said, the iPhone 4 has perhaps the most refined web browser of any smartphone we’ve tested, even if it is a bit slower than the Thunderbolt in loading web pages.
Call quality is important, and both devices provide great call quality (that’s assuming you have reception on your AT&T iPhone 4!). The iPhone 4′s speakerphone is slightly better than the Thunderbolt. Both offer noise cancellation.
In terms of data speeds, there’s no contest: the Thunderbolt can achieve download speeds that are 3-6x times faster than what you can get on AT&T, thanks to Verizon’s 4G LTE network.
And finally: battery life. You’ll definitely get better battery life on the iPhone 4. It can go about a day and a half with heavy usage, while the Thunderbolt will need to be charged once per day if you’re using it a lot.
In the end, it’s a matter of priorities: if you want the fastest phone with the best data speeds, plus a spacious screen, the Thunderbolt is a great choice. It’s also a better value. But if you want a more refined device that has the best screen possible, all in a relatively petite package that won’t leave a huge bulk in your pocket, the iPhone 4 is your best bet.