No noticeable changes have been seen in this update, it does not include the apps to SD card feature that appeared in the Xperia T2 Ultra KitKat firmware. At the moment it appears that there is no way to root this firmware, so you may want to hold fire on updating right now. If you want to give it a try you can download the FlashTool FTF firmware from here.
Update: Sony has now updated its product page with a changelog:
– Enhanced voice call quality
– Improved touch function and performance
– Charging improved when battery is low
– Overall performance and stability improved
– And all of our latest bug fixes and improvements
Via XDA.
Thanks Andrea!