Mine's been fine with battery.. Usually between 23-50% at end of day.. and I start at 5am and end usually around 10-11pm at night.. 30 min of exercise in there, a few voice calls, avg 6-10 emails/texts notifications per hour throughout the day, etc.
Have yet to run out by the time I call it at end of my day. So far, I love it.. I've permanently turned my 6 plus on mute now and filter it all notifications with my Apple Watch. Really liking it.