Battery is fantastic for me. Usage varies from day to day though, but I don't use it for more than 3 screen on hours a day. I usually end up with about 50-60% left by 10:00 PM after unplugging at 6:30 AM.
Battery is wonderful on my 6+. Lasts all day with me being on it most of the time from 7am until around 11ish when I go to bed and still have 40% left. If I wasn't such a heavy user, I know it would last almost 2 days.
Battery life gonna differ from one user to another. If you're seeing an increase from previous device with same settings and usage profile you're good to go. Turn the battery % thing off and enjoy the phone.