I'm comparing my wife's 5 to my 6+I can only compare to my iPhone 6 which the battery does last 40% longer if not more.
Battery size differenceCharging them full in the evening, in the morning the 5 is down to about 80%, the 6+ is still 100%.
Can't see what's eating that much, there's no listing which apps were using the battery.
Both phones are on iOS 10, should show the consumption but they don't.but I think the power consumption details were there before with iOS 10.0
I've never had an issue with doing it. Simply do a full backup, put the phone into DFU mode and plug it in.Risky. Even with a good backup little to gain, a lot to lose.