I have 4 big problems with the latest update:
1) When in Extended Standby Mode and Wifi is set to be "On during sleep" - it just doesn't work after turning on the screen. I need to turn off and on wifi to make it start work. This problem doesn't exist when Wifi is set to be "never" on during sleep - then everything works fine (but it uses more data)
2) Battery drain - although it is better then on ICS, sometimes from unknown reason it starts to drain terribly on standby mode. I have installed same apps which I had on ICS so it's definitely JB upgrade bug. I have full signal, and internet off. One time my phone can stand 4 days, another it is barely one (with the screen on for 40 minutes, and internet off !!!)... from what i know a lot of people have similar problem.
3) Launcher redraw - each time I exit browser or Facebook app all of the icons disappear and phone is loading launcher again. It is so annoying - this phone have 1 GB of ram and it works like my previous Xperia x10 with 384mb... This problem didn't exist on ICS.
4) Facebook app - you will probably say that it is Facebook fault but it started to behave strange right after JB update. It drains at least 20% of battery in standby, and works very slow. What is more it uses around 200mb of ram - i had to uninstall it and use browser version. I find it quite funny anyway - this is not what i expected from an ex flagship.
Of course I am not mentioning 2G and Full HD recording - it is obvious that it needs to be repaired...
