Sony announced the X series at Mobile World Congress in Barcelona, comprising three new smartphones. The company also confirmed the Z series will end with the Xperia Z5, leaving the new X range to take over. 

The Xperia X Performance sits at the top of the X series, although sadly it won't be making its way across to Europe or the US, stopping its journey in Asia. That's not to say it isn't important though, because in actual fact, the X Performance could very easily have been the Xperia Z5's successor.

With that in mind, we have decided to compare the two devices to see where the difference and similarities are. How does the Xperia X Performance stack up against the Xperia Z5 and would it be worth the upgrade if it ended up in our waters?

The Xperia X Performance measures 143.7 x 70.4 x 8.7mm and it weighs 165g. It trades the frosted finish that comes with the Xperia Z5 for an aluminium finish on the rear and adds a glass overlay to the front.

The same OmniBalance design is still present, along with the signature side power button that incorporates the built-in fingerprint sensor that Sony introduced on the Z5. In fact, aside from the materials and the rounder edges of the Xperia X Performance, these two smartphones look very similar. They both offer the capless Micro-USB and waterproof and dustproof ratings of IP68 and IP65.

The Xperia Z5 is a little larger than the X Performance, but it is also slimmer and quite a bit lighter. The Z5 measures 146 x 72 x 7.3mm and hits the scales at 154g.

The Xperia X Performance comes with a 5-inch display, which is a little smaller than the 5.2-inch display found on the Xperia Z5. Both have Full HD resolutions, which means the X Performance is ever so slightly sharper at 441ppi in comparison to the Z5's 424ppi. This will not be noticeable to the human eye at this size however.

Both devices have the same Sony technologies on board, including Triluminos and X-Reality. Despite being only 0.2-inches smaller than the Z5, it is worth mentioning the X Performance is a little easier to manage and the display size seems to suit the design of the device a little better. 

Aside from that however, you would get a very similar experience on the Xperia Z5 and X Performance when it comes to display.

The Xperia X Performance features a 23-megapixel rear sensor with 24mm wide-angle G lens. It offers sensitivity up to ISO 12800 and it comes complete with HDR and Superior Auto+, as well as a new software feature called Predictive Hybrid Autofocus. This latter feature allows the camera to track and predict movement, with the idea being that you never miss a moment because the camera has already shot it.

In terms of rear camera, the Xperia Z5 is the same. It also offers a 23-megapixel sensor, 24mm wide-angle G lens and sensitivity up to ISO 12800. It doesn't offer the Predictive Hybrid Auto Focus feature however. 

The front cameras are different. The X Performance comes with a 13-megapxiel front snapper offering an aperture of f/2.0 and sensitivity up to ISO 6400. The Z5 on the other hand has a 5-megapixel front camera with a narrower f/2.4 aperture. This should mean the X Performance would be better at capturing low light selfies but in terms of the main camera, you should get a similar camera experience as the Z5 aside from having to keep a closer eye out for those special moments.

The Xperia X Performance comes with the Qualcomm Snapdragon 820 processor, supported by 3GB of RAM and 32GB of internal storage. There is a microSD slot for storage expansion and a 2700mAh battery powering everything. 

The Xperia Z5 features the Qualcomm Snapdragon 810 processor, 3GB of RAM, 32GB of internal memory and microSD support so the same as the Xperia Z5, aside from the newer and faster processor in the X Performance.

There is also a slightly larger battery at 2900mAh in the Z5 but considering the new processor, we suspect there won't be much difference in actually battery life, with both devices claiming to offer up to two days.

The Xperia X Performance will launch with Android Marshmallow from the box. There should also be a few software changes but it is unclear what these will be at the moment as the devices at MWC were not final software. 

The Xperia Z5 is currently on Android Lollipop but it will eventually get an upgrade to Marshmallow, and more than likely any of Sony's own software updates. This should result in a very familiar experience between the two devices.

The Xperia X Performance is the smaller and faster of these two devices, but it is a little heavier and thicker than the Xperia Z5 and it offers a smaller battery capacity. The X Performance does have a more streamlined and exciting design with the metal finish however.

You would probably also get better selfies with the X Performance over the Z5 but the main camera performance should be pretty similar, as well as the software experience and display.

Would the X Performance be worth the upgrade? If you were moving from the Xperia Z3+ then absolutely. If you were moving from the Z5 and wanted a nicer design and the latest processor, as well as camera improvements then probably. The X Performance makes the updates in the places that matter but the Z5 is a good device in its own right. Lucky that seeing as unless you live in Asia, you can't upgrade anyway.