Hello ! I'm using iPhone 6 plus 64 gigs , and I on iOS 8.3 I didn't update because I was reading here that people compliant about battery drain . My iPhone the battery life on iOS 8.3 almost full day with very hard use like YouTube ,browsing the web , some games , and ofcors music . So my question is if I update to iOS 9.1 is my battery life will be the same or should I wait until they will realese 9.2 ??? Thank you !