Bought it on April 2015 and still using it.
Sony is always good in sound department so no doubt about it.
Battery Backup almost same as 2yrs back.
I’m not satisfied with the Camera though. Camera app is very slow.
I recently Format the phone and after that it started working as new.
If anyone using this phone and having Hang or Slow issue then I will recommend you to format it after taking BacKUp.