Sony's Xperia X phones have been boring, overpriced and underwhelming. But there's reason for cautious optimism.

Sony, and before it Sony Ericsson, has been part of the Android ecosystem almost since the very beginning. Along the way, despite tumultuous conditions elsewhere in the company and a hit-and-miss biannual release cycle, Sony has managed to turn out some genuinely great handsets. The Xperia Z3 stands out as the zenith of that series — the last Sony phone that was really worth a spot next to the Galaxy phones and iPhones of the time. (And a model that holds up so well two years on that it's the only Sony phone currently involved in the Android 7.0 developer preview program.)

But over the past couple of years the Xperia series has stalled. The Z3+ was a mess of thermal and performance issues. The Z5 was decent, but looked tepid next to its immediate competitors.

Sony in 2016 so far: Boring, overpriced, disappointing rectangles.

Enter the Xperia X in 2016, with a new strategy and leaner phones focusing on user experience, with less overt spec-chasing. It seemed like a good idea at the time — the Xperia X was to be a Moto X-style "phone of the people" that would make up for its lack of bleeding-edge specs with intelligent software.

What materialized was another boring, Android-powered rectangle with obvious hardware issues. Plastic-framed in an age of metal and glass, with a slow camera that disappointed in low light, and at a $550 price point that made sense to nobody besides the hardest of hardcore Sony fans. You could get the same user experience elsewhere for a fraction of the cost.

Xperia X family

Similarly, its big brother — the X Performance — offered little over the X to justify its eye-watering $700 price tag. The touchscreen was plagued by sensitivity issues. The same camera module from the X was used, so low-light photo quality disappointed next to the Samsungs and Apples of the world. Even with the latest Snapdragon 820 under the hood, the camera was painfully slow to load and to shoot. Once again, there was basically no reason to give Sony your money in a world where the Galaxy S7, HTC 10 and iPhone 6s exist around the same price point.

And buyers in the United States got a bum deal, paying $550 for the Xperia X, or $700 for the X Performance, with no fingerprint scanner — a hugely important feature included as standard in other territories.

That Sony, a brand with a strong pedigree of excellent standalone cameras, and the manufacturer of sensors used in the iPhone 6s Plus and Galaxy S7, is still making the same mistakes in its own mobile cameras, is mind-blowing. Going against the established wisdom of the industry, it's still acting like optical image stabilization doesn't matter, and that you can ship a traditional high-res sensor without OIS and rely solely on software.

It's also shocking that a veteran manufacturer decided to exclude such a key feature as fingerprint security from its flagship phones in a market as important as the U.S., in defiance of a broad and obvious industry trend.

At this point, the Xperia X series' only differentiator is the Sony brand itself.

The company has also been walking back its other major differentiator: battery life. In the days of the Xperia Z1, Z2 and Z3, Sony could legitimately boast of industry-leading longevity. Its big, boxy phones were able to hold big, boxy batteries that could go all day and then some. Battery capacity has been slowly eroded in the intervening years, and now the Z3+, Z5 and X will get you a single day if you're lucky.

Bringing cutting-edge Sony tech to cellphones was the mission statement of the old Sony Ericsson. As recently as 2015, Xperia phones were being marketed as being "the best of Sony." But the Xperia X series isn't the best of anything, and increasingly the only real differentiator these phones have is the Sony brand itself — a brand which, let's face it, no longer carries the cachet it once did.

Sony needs another big, impressive phone. Something worthy of a top-tier price tag and and something to justify the value it places in its brand. Something which isn't as aggressively meh as its recent efforts. And as someone who's used and loved Sony phones in the past, I really hope this leaked handset is the product to do that.

We don't know much about the Sony F833X at this point besides its model number and a handful of leaked photos. (Like almost everything else, it'll supposedly use a Qualcomm Snapdragon 820 processor.) However the pics obtained by GSMArena are revealing in themselves.

This leaked Sony phone looks like a bit of a tank — but that's fine if it packs the hardware to justify its heft.

It's a big, blocky phone — a throwback to older Xperias, perhaps, with room for a hefty battery inside. The device's thickness also bodes well for camera performance — there should, finally, be space for an optically stabilized module while still keeping the lens flush with the body. Other noteworthy camera improvements — dual-LED flash around the back and laser autofocus — suggests meaningful steps forward have been made here too.

And while it is thick, rectangular and tall, horizontal bezels have been kept to a minimum, and the design language seems to have moved on. Parts of the chassis may be plastic, but the frumpy polycarbonate trim of the Xperia X seems to have been largely eliminated. It looks like a bit of a tank, and that's just fine if it packs the hardware muscle to justify its heft.

If the Xperia X is going to be the phone for the masses (still a tough ask at $550, admittedly) then this new model (an Xperia X Ultra, maybe?) could be the Sony phone for enthusiasts. That's what I'm hoping for — an Xperia phone to reinvigorate this tired brand, with hardware, camera chops and battery life to get excited about.

It's possible the Xperia X Ultra (or whatever it's called) will break cover as early as IFA 2016 in early September. And if it lives up to our hopes, it could make a interesting addition to the fourth-quarter flurry of new smartphones. If not? Well, maybe it's time to dust off the Xperia Z brand for a 2017 revival.