I like mine on. I don;t obsess over it because there is almost nothing you can do. People think it's stuff running in the background, but it is very few and far between that an app is truly running in the background (basically this is limited to GPS and music apps essentially by design). Then again, I am not finding that my battery life is any worse than it was on my iPhone 4. The percentage is handy to me because if I used the phone heavily, am not able to charge, and I know I will need to use it again for something important later that day before charging, I can make a quick mental estimate whether I can keep using as heavily I am or if I should taper off a bit to make sure I have the juice I will need for later.