Specs at a glance: Sony Z Ultra Google Play Edition Screen 1920×1080 6.4" (342 ppi) IPS touchscreen OS Android KitKat 4.4 CPU 2.26GHz quad-core Snapdragon 800 RAM 2GB GPU 450 Mhz Adreno 330 Storage 16GB or 32GB Networking Dual Band 802.11b/g/n/ac, Bluetooth 4.0, GPS Network GSM (850, 900, 1800, 1900 MHz); HSPA+ (850, 900, 1700, 1900, 2100 MHz); LTE (700, 850, 900, 1700, 1900, 2100, 2600 MHz) Ports Micro USB, headphones Camera 8MP rear camera, 2MP front camera Size 179mm x 92mm x 6.5mm Weight 212g Battery 3000 mAh Starting price $650 off contract Other perks RGB notification LED, waterproof, MicroSD slot

How big is too big? Android device manufacturers continue to push the boundaries of what can be considered a smartphone. Pocket-busting devices like the 5.8-inch Galaxy Note 3 and the 6-inch LG G Flex are becoming more common, and 5-inch devices seem to be the new "normal" with the Galaxy S4 and Nexus 5 both clocking in around that size. When it comes to the Sony Z Ultra though, we think everyone can agree: this is way too big.

The device is a phone, with a cell modem, microphone, and earpiece, yet the screen size clocks in at a massive 6.4-inches. This device is closer to the size of a Nexus 7 than a Nexus 5. Fitting it into a pocket is a ridiculous prospect. Even in baggy jeans, the corner usually sticks out of the pocket, and it hinders walking motion. One-handed use is out of the question. The Sony Z Ultra is more like a tablet with built-in data, and if there is a huge emergency you can begin to consider making some kind of phone call.

The Sony Z Ultra is a Google Play Edition (GPE) device, which means it runs stock Android (KitKat) and should get pretty speedy updates—if the past is any indication, new versions of Android should hit the device about a month after release. All GPE devices are sold through the Google Play Store unlocked and contract free. Sony is a perfect fit for the Google Play Edition program. The company's software is usually pretty heavy, and it has a hard time keeping up with the Android development cycle. Sony also typically has trouble getting carrier deals, so much so that it's significantly reduced its presence in the US market to focus on countries where unlocked devices are the norm.

Beautiful Hardware

The Z Ultra is a beautiful device. Sony's tablet is a simple, black square with only minimally-rounded corners. The only marks are a Sony logo on the front and back, a rear camera lens, and an NFC target. The front and back are entirely covered tempered glass, if it weren't for the logos and camera lens, it would be impossible to tell the front from the back.

The Sony Z Ultra is extremely thin—at just 6.5mm, it's one of the skinniest mobile devices ever. Combined with the front and back glass and the spectacular build quality, and the Z Ultra feels like holding a solid pane of glass. Dropping it would probably be a terrible idea, but it feels like a quality piece of hardware.

The device is so large that Sony has smartly chosen to put the side power and volume buttons toward the center of the device, rather than the usual placement at the top. The shiny silver power button is the only standout button on the "phone." Oddly enough, in the above picture the device is face-up, but the power symbol is upside down from how it is typically oriented. The same goes for the "Micro SD" logo.

About that MicroSD slot: while you can put a card in it and the Z Ultra will read it, stock Android doesn't really support MicroSD cards anymore, so the card is mostly read only. If you root the device you can make use of it, but without root, the only way to write to the card is to hook it up to a desktop computer and copy files over.

Update: KitKat actually has new APIs to support SD cards, most apps just don't use them yet. Each of your favorite apps would need to be updated for compatibility.

The Sony Z Ultra is waterproof, which means having to deal with annoying port covers. They're necessary for waterproofing (and must be properly closed to be waterproof), but they're the one cheap-feeling part of the device. The flaps are held on with little strips of plastic and cover the MicroSD Slot, SIM slot, and MicroUSB port. The flaps over the USB port make charging even more of a pain especially if you're used to wireless charging, which the Z Ultra does not support.

The waterproof aspect is strange. It will save the device from an accidental bath, provided the port covers are on securely, but the Z Ultra isn't usable underwater or really even while wet. Any water on the capacitive touch screen causes random screen input and starts randomly launching apps, typing things, or triggering a pinch zoom.

On the back you'll see the 8MP camera, but there's no flash. Flashes in most smartphones are pretty bad, but we would rather have a flash than not have one.

The sides of the device are a hard plastic. The above picture is of the bottom dock, which has a magnet and charging connectors for Sony's dock accessory. To the far left of the port is the cover for the MicroUSB port, but to the right of the port there are lines for seemingly no reason. It looks like a removable port cover, but it's just hard plastic with lines it in. The only explanation is that Sony was aiming for mirrored symmetry with the fake port cover. It's the same size as the MicroSD/SIM cover on the other side, but that is toward the top of the device. This "fake cover" is toward the bottom.

Top edge has a secondary microphone on the side. The cutout is bigger than it needs to be, again, for symmetry with the bottom edge, which houses the cutout for the speaker. The symmetry theme continues with the primary microphone and earpiece, which both sit centered on the top and bottom edge of the device. One of the most unique features is in the bottom left corner, which has holes for a lanyard attachment.

Like most modern smartphones (and unlike the LG Flex we just reviewed), the display on the Z Ultra is gorgeous. The 6.4-inch, 1080p IPS panel clocks in at 342 ppi, which sits nicely between the 2013 Nexus 7's 323ppi and the Nexus 5's 445ppi. The tradeoff with larger screens is always a lower pixel density, but you still won't see a pixel on the Z Ultra.

Since the display is an IPS LCD, the pixel layout is a pretty normal RGB stripe. Sony's display is bright and the colors are accurate, you'll hear no complaints from us.

Stock software, but in desperate need of an OTA update

There is not much to speak of on the software front. The Z Ultra, like all Google Play Edition devices, runs stock Android 4.4 KitKat. It's a fantastic software package, which we've already fully reviewed here, so we won't bother repeating ourselves.

There are a few differences over the Nexus 5 loadout. The Google-Search-powered home screen is still a Nexus 5 exclusive, so the Z Ultra gets an old-school Jelly-Bean-style launcher with black navigation and status bars. There are still "app" and "widget" tabs in the app drawer.

One of our biggest complains about KitKat was that there were two very-similar photo apps: the Gallery and Google Photos (a section of the Google+ app). The Z Ultra (and the other new Google Play Edition device, the LG G Pad 8.3) has removed the Gallery, and pictures are handled entirely by the photo section of the Google+ app. Swiping over from the camera to other photos works just as it always has in Android, but the Google+ app has been seamlessly dropped in in place of the Gallery. The advantages are a single photo app, and easy management of your cloud-stored photos.

If you don't like Google+ you probably won't like this change, but for most people, having the app that automatically backs up all your photos also manage your camera roll makes perfect sense. If you don't sign in to Google+, the photos app is completely usable as a local photo viewer. You can share to other apps, use the editor, and manage files all without signing in to Google's social network. So if you would prefer to avoid G+, you can.