Unsurprisingly it is the biggest of the three handsets that commands the biggest price - with size predicting cost of device.
The Xperia Z Ultra will set you back a considerable amount SIM free, somewhere between £400 and £500 depending on where you look. Sony's Xperia Z1 will set you back between £400 and £540 with the Z1 Compact coming in at about £400.
It would be all too easy to sum up the differences between the Sony Xperia Z Ultra, Z1 and Z1 Compact in the screen size yet Sony has left little for these superb devices to be judged upon. A lot of the judgement in which device is right for you will stem from what screen size suits you.
As with every phablet, the Sony Xperia Z Ultra fits perfectly in the gap for those that want something that they can watch movies or play games on during the morning commute whilst also being able to make phone calls and browse the web.
The superb screen makes it ideal for watching movies from a variety of angles and is bright enough and clear enough that you won't be left wishing you'd opted for a tablet. That said there will still be a few funny looks if you try to hold the Z Ultra to your ear to make a call.
Sony's Xperia Z1 is far more suitable for those that are looking for a well designed and well built flagship handset with a massive camera. The 20.7MP sensor that graces the Xperia Z1 produces some of the best photos that we have seen from a smartphone.
The 5-inch screen is more than adequate for watching movies and the pin sharp screen makes reading text a lot more friendly on the eyes. As an all rounder there are few better than the Xperia Z1.
For those looking for a smaller handset but without the compromise of smaller powered insides the Xperia Z1 Compact is the more logical choice.
It takes the best of the Sony Xperia Z Ultra and Xperia Z1 and crams it into a much smaller, and more pocket friendly, frame.
It is also the most inconspicuous of all three handsets, unless of course you grab the lime green or pink version. Being more pocket-able also means that it makes an easier replacement for the traditional compact camera.