Here is a dissenting account: iOS 10 DP III has been buttery smooth for me, and while battery life is slightly below par, it is generally understood that it will even out or exceed the battery life of the previous software version. YMMV.
Not sure if this has been mentioned elsewhere, but I noticed that sensitive information contained in widgets, such as activity data, is restricted until you Touch ID to unlock. It also appears that the padding between the Music peek and pop options have been condensed into one bubble. These may have been previous editions, but they stood out to me after updating.