Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I'd say my battery life for iOS 8 beta 4 (on my iPhone 5 and iPad Mini) is pretty good (isn't great compared to iOS 7.1.2) but still. I'd give it a 7/10 rating. The Battery Usage tool is nice but it would be even better if it went into a little more detail. "Home & Lock Screen" is pretty vague.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.