I got to play with the 5S yesterday. The touch ID really works well, and it's easy to set up. I read many bloggers like anandtech, allthingsd, and more, stating that the touch ID feature is better than they originally thought it'd be.
iOS 7 is a really nice upgrade for the iOS. The pop up toggles was way over due but done nicely now that it's here. The notification center on first look seemed to be crowded, though i didn't really use it too much to see how it performs. The biggest issue I had was closing apps by swiping up; it felt like you needed the right angle for it swipe up and away, when you don't really wanna consciously think how your swiping.