So far I haven't seen this stellar battery life...it's no worse than the 5S, but if it is better, it's not by a whole hell of a lot really (in my case). Went for a ride, using Map My Ride...I usually go about 14-15 miles on this particular route and my 5S would lose about 25% of it's battery life over the entirety of the ride (GPS, music, etc going the whole time). iPhone 6 Plus lost about 22%.
Now I like to give a device the benefit of the doubt because when you first get it, you're playing with it A LOT more than you normally would (especially when it comes to settings), so I'll reserve my opinion until I have some legitimate usage. This small sample size really doesn't prove anything one way or another to me.