First thing you will notice about this phone is the size,6.4 inches,ie a little smaller than the nexus 7's size. But this is a phone and not a tablet. Carrying around this phone would be very difficult unless you make some special pockets to slide that huge phone in.
Features,Pros and Cons
Great Huge 1080P Display with great viewing angles.
Good built quality - Very thin
Powerful 2.2GHz Snapdragon 800 processor - This same processor powers Nexus 5.
2GB of RAM
16GB of internal storage + Micro SD card slot
Camera quality is not very great,often produces washed out images. This thing doesn't have a flash to assist low light photography.
3000mAH battery - This is a must have,but still last only one day of average use since it has to power up such a huge,pixel dense screen.
A pen or a pencil can be used to write on the Xperia’s display to convert handwriting to text.
Faster Android Updates - Sony has already pushed out 4.3 update for this,and are working on 4.4 update.
This is one of the greatest phablets ever produced,but its very expensive,huge and lacks some features. Note 3 comes with a better camera,better battery backup and a stylus which makes it a better buy than Ultra. But if you are a Sony fan,and want something huge to 'show off' this is the ideal device,ofcoz if you have enough money to get one .