I have a 6s and not having that battery issue - it is at least as good if not better on 10 than 9. Have you checked setting, battery to see what app is using the most battery for you.
I have iPhone 6s and ios 10.0.2 and i dont know if its inly me but if i get 3 hours of Usage and 3 hours of standby and battery is at 40% im not that happy with it :/
Yea but i do need the processing power and the background refresh sometimes so its not the ultimate solution, and iOS 10.1 is all about the Plus iPhones models , so i guess we'll have to wait for iOS 10.2 :/