Share your experience!
Are you talking about life on stamina mode?
It depends on the processes going on at the time,wifi,data,bluetooth and other factors like luminosity,bravia engine etc.
Do you have any task killers or battery savers?
Remove it,see how it goes.Also,restart your phone often.
There must be some apps acting up.Have you tried booting your phone in safe mode?
http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008