I noticed right away that my battery doesn't drop within the first 5 mins of disconnection from charging like it did before. Left it overnight on standby with the screen off and this morn was still fully charged. Thats an improvement I think. Half a day later, not having run much its at half charge. I never had a problem with calls dropping before. The backup is definitely allot faster too. Good improvements apple. One thing I've found is poor reception FROM the iphone when others are on the other end listening. Their signal was clear, but they heard a breaking up "warbling" distortion. This was from about 20 miles and I was indoors, so yet to find out if this has improved. If there are ways to extend the battery even more, please do, this is the only real flaw.