Like Samsung, Sony is yet to update a single Lollipop-powered device to Marshmallow outside of “Concept” beta programs, although we were ready to wager at one point a number of 6.0 rollouts would begin by the end of January for Xperia flagships.
Meanwhile, the Japanese hardware manufacturer reconsidered the direct leap plan from Android 5.0 to build M for a couple of lower-end handhelds, but the Sony Xperia M4 Aqua isn’t a part of the group ultimately due for transitional 5.1 Lollipop promotions too.
Instead, the waterproof 5-incher will continue to sit tight on ancient 5.0, waiting for its 6.0 package to be optimized and dispatched over-the-air, which is unlikely to happen anytime soon. Our guess is M4 Aqua owners need to stay calm and patient at least three or four months further, a situation that definitely falls under uncomfortable and unpleasant but not altogether unexpected.
After all, the mid-range phone is almost a year old, it’s already been followed up by a superior M5, and only costs $200 unlocked with a valid US warranty on Amazon. Speaking of, maybe this is your best opportunity to nab a cheap, relatively powerful and good-looking Marshmallow-ready device. Don’t blow it, and don’t hesitate too much, given the price tag’s listed as a discounted affair, possibly with an expiration date attached.