I've done absolutely everything, restored as new phone, replaced the phone, changed settings. everything. Still can't get more than 5-6 hours of usage and like 10-12 hours of standby.
Disable LTE and you will double your phone life.
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Mine works flawlessly so far. What do you mean?
Two things wrong:
1.) No delete song on swipe any more.
2.) On iPad, covers get corrupt over time and show up blank (a few covers a day), only fix is to delete your entire music collection and download again over iTunes match.