If you've been poking hopelessly at the Sony Xperia Z1's 5-inch screen, your oddly massive hands far too unwieldy to accurately stab at any one icon, the Z Ultra might be just the phone for you. It takes the Full HD screen, quad-core processor and waterproof body of the Z1, but stretches the display to a whopping 6.4 inches across.
It also packs an 8-megapixel camera and 4G connectivity for fast data downloads. It's listed on Sony's website at a pricey £600, which is loads to pay for a phone, even with such a huge amount of glass on the front. If you shop around you can pick it up for less however -- Play.com lists the device at a more reasonable £460.
Alternatively, you can get it free from £29 per month on a two-year contract.
Design and build quality
Okay, I'm just going to say it -- the Z Ultra is absolutely enormous. It's a 6.4-inch phone, measuring a whopping 179mm long and 92mm wide. Up close you'll struggle to decide if it's a phone or a tablet and you'll no doubt feel a certain degree of embarrassment holding it up to make a call in public.
I argued that the 6-inch Nokia Lumia 1520 was too big as it's almost impossible to use properly with one hand. The Z Ultra is considerably bigger due to its larger screen and its fat bezels. It's definitely a phone for two-handed use.
While the size makes it good for watching video, you should seriously think about whether you can cope with permanently carrying around such a vast phone in your pocket. It makes sense, however, that the Galaxy Note 3 is so large as the included stylus allows you to write on the screen like a notebook. The Ultra's screen is super-sensitive though, letting you use even a pencil as a stylus. It's not as accurate as Samsung's S Pen, but it's much better than using a finger.
It is at least very slender, measuring only 6.5mm thick. It looks good too, with its all glass front and back, and stark, minimalist design. Like the Z and Z1 it's waterproof to 1 metre for up to 30 minutes, meaning it won't give up the ghost when you spill a pint on it or drop it in the bath.
The Z Ultra comes with 16GB of storage space -- although usable capacity is a little less as the operating system takes up some space. It does have an SD card slot to store videos and music on though.
The screen has a 1,920x1,080-pixel resolution, making it Full HD. Both the Z and Z1 had Full HD screens, but as they're both smaller, they pack their pixels tighter, making them slightly sharper. You probably wouldn't be able to tell the difference though as the Ultra is still very crisp.
Icons are sharp and small text is easily readable. It's bright and has good colours too, making it great for swiping through your holiday shots on Flickr or watching Breaking Bad on Netflix. You can turn on an image quality 'enhancer' in the settings too, although I found this made my test photos look slightly oversaturated and unrealistic. It's a much more pleasing screen without this boost.