I haven't really played with iOS7 enough to make much comment about the new features.
BUT, the one thing I have spotted almost immediately is that the new thin typeface used is all but unreadable in bright daylight. I find it hard to believe that with all of the testing that Apple supposedly do, that this has not caused difficulties for any testers.
Shame really that such a fundamental part of the interface should appear to be a backward step.
That, and the surprisingly odd iPhone 5c which doesn't seem to fit into any sensible marketing or business strategy, makes me wonder whether we're seeing the impact of Steve Jobs' demise far faster than one might have expected.