It's been a week since I upgraded my iPhone 5 to iOS 8.3. I was hesitant at first due to mixed reviews. The consensus seems to have been "wait and see", specially with iOS 8.4 around the corner. But I've been experiencing poor battery life since iOS 7 to iOS 8.2, always having to recharge by midday. So I thought I had little to lose -- most of the issues on iOS 8.3 were related to touchID which the iPhone 5 doesn't have. I'm glad I upgraded. Battery life has been a vast improvement, I'm back to one charge cycle per 24 hours. My guess is the better management of apps in the background. Good job, Apple!