The update is being pushed through the Sony PC Companion software suite and weighs in at around 770MB. Make sure that your device has at least 50% of its battery life before you initiate the update. The full change-log offered in this update follows
- Overall performance increase and improvements in battery life
- New stock widgets – Clock, Alarm Clock and Calculator among others
- Multiple small apps can now be opened at once
- Refreshed design as far as the messenger and e-mail apps are concerned
- Superior Auto mode added to the camera appearance
- One-handed text input now possible
- Background UI has gone white-grey
The Sony phablet flagship features a 6.4 inch touch display, 16GB of internal storage which can be expanded through microSD, an 8 megapixel camera capable of 1080p HD video capture, a secondary 2 megapixel camera for video calls. NFC, 4G LTE connectivity and is powered by a 2.2GHz quad-core Snapdragon 800 processor with 2GB of RAM.
source - XperiaGuide