Painfully slow S3 with bad battery life
I just came home from college and tried to use my dad's S3, and found it to be surprisingly slow for a phone with those specs. Also he told me the on screen time is around 2 hours for him.
I myself have been using Android phones (including an S3 in the past) for a long time, and I've never experienced such a slowdown.
1. What could be the cause of this? Unavoidable periodic bloat/slowdown? Maybe some sort of malware/bloat (I won't rule my dad out from falling for sketchy looking apps)
2. Any tips or suggestions on how to fix this? Or is a factory reset the only way?
3. Is there any pure Android ROM (without TouchWiz) which is as stable as the stock ROM? Keep in mind it would be my dad using it and I can't really expect him to reflash by himself in case he encounters a major problem.
Phone History: Nokia 6600 -> Sony Ericsson W850i -> Sony Ericsson W300i -> HTC Touch -> LG Optimus One -> Sony Ericsson W8 -> Nexus 4 (broken) -> Galaxy S3 -> Galaxy Note 2 -> LG Optimus One -> Nexus 5