Sony came up with the company's current design aesthetic a while back and closely sticks to it with the Xperia Z4 Tablet. It's dubbed OmniBalance and its roots could be traced to the original Xperia Z smartphone introduced more than two years ago.
Now there surely will be those that insist that it's a long time for a design to remain unchanged in today's fast moving world. While there's some truth to that, there's no denying that the Xperia Z4 tablet is a looker of a slate.
It is more or less the Xperia Z2 tablet with a few minor tweaks. The front is glass as usual, but the bezels have been trimmed down and the tablet has lost 12mm on the long side and 5mm on the short. Notable differences and ones that are readily noticeable in reality. There's a Sony logo in the top left corner, the 5MP front camera is right in the middle joined by an ambient light sensor, and the notification LED is the top right corner.
On the front, towards the edges of the short sides, you can find the thin slits, where the stereo speakers reside. A welcome design move sees the speakers positioned some 3cm higher than in the previous generation, where they were easily muffled. Only it would have been nicer if they were even further up, perhaps somewhere in the top third, because as it stands, there are still cases when you put your palms right on top of them.
The back borrows its design prom the predecessor too. Sony adopted matte plastic for the tablet lineup as opposed to the glass on the smartphones, deeming it much too hard work to keep all that vast shiny surface clean. Indeed, the soft plastic looks good and is less prone to accumulating fingerprints, but it's not all that easy to clean once it does get dirty. We're not sure how the white model will fare in this respect.
Sony has gone quite minimalistic with the back. There's a small company badge dead center and an even less conspicuous Xperia inscription below. The main camera lens sits in the top right corner and the position of the NFC antenna is marked with a tiny logo, relocated compared to last year. Sony has gotten rid of the regulatory markings and stuffed them in a tiny label inside the slot compartment, like it did on the Z3 Tablet Compact.
The left side is home to the power button and volume rocker, both in a very natural position for your left thumb when holding the device in landscape orientation. On the right you'll find a lone microUSB 2.0 port, which now has no flap.
The top left corner (when viewed from the front) is where the 3.5mm headphone jack is located, moved from the bottom left, where it would have interfered with the optional keyboard dock, but more on that later. To the right of the jack is the slot compartment. Behind a flap, meant to provide the IP68 sealing, you'll find the nano SIM and microSD slots. The single mic is further towards the center. The bottom is completely bare.
The Xperia Z4 Tablet is nothing short of impressive when it comes to thickness and weight. The 6.1mm profile, coupled with less than 400g of heft mean that Sony's offering is as close to comfortable single-handed use as we've ever seen from a 10.1-inch slate. Longer reading in portrait is not a problem, though in landscape the center of gravity is further away and thus puts more strain on your wrist.
With both hands weight becomes a non-issue. In landscape, however, there are cases when you could end up muffling the speakers, unless you're careful to keep them in between the bases and the tips of your thumbs. Or you could rotate the whole device upside down and forget about it.
The bezels are adequately sized, so that you have enough area to establish a secure grip, without being unnecessarily large. The back surface is grippy enough as well.
Alongside the Xperia Z4 Tablet Sony announced the BKB50 snap-on keyboard dock which turns the tablet into a compact Android netbook. The keyboard weighs 365g and thus the pair totals around 760g and 13mm. At the hinge it's slightly thicker, obviously. Sony claims you can get a month and a half of battery life out of the keyboard's 400mAh cell when used for 8 hours a day, but we had no practical way of confirming it.
The tablet fits securely in a cradle, which is hinged to the main body of the keyboard. The hinge is quite tough to turn without a tablet inside, but that's not how it's meant to be used and with the Z4 Tablet attached, the force required is just right. The entire assembly clicks positively in the closed position and offers up to 130° tilt angle when fully open.
The keyboard communicates with the tablet via Bluetooth and the initial pairing can be done via or manually in the Bluetooth settings of the tablet. The keyboard apparently has a sensor in the hinge, which sends the tablet to sleep when closed, and wakes it up when opened.
The BKB50 has a full QWERTY layout with a number row and function key row. The key spacing is roughly 16mm, as opposed to the 19mm of the regular full-sized keyboard but it's still comfortable to use and there's no room for comparison to an onscreen keyboard. You also get keys that double the onscreen Back/Home/Task buttons.
It's a chicklet-style keyboard and the keys have adequate travel and offer positive feedback. There's also a nice touchpad with button areas on the bottom, but not actual discrete buttons.