Even iOS 5 adds a lot of niceties for developers. I am absolutely in love with storyboarding and so are the non-programmers on my team.
And as badly designed Game Center may be, I have been playing Letterpress all day on it with only one hiccup. It can't be _unusably_ bad anymore on iOS6. The author of Letterpress found nice words for it too[1].
Storyboarding strikes me as an example of another problem; it's very nice, but so poorly documented that it can be unclear how to do anything non-trivial with it. There are also a few deficiencies which require ugly hacks.
I think the award in that category goes to NSIncrementalStore :) I could often guess what I had to do in an overridden method...but in some places, I am still scratching my head.
Part of the reason I don't even use storyboards is because of its lack of good UIView manipulation. I do a lot of things in container views and scrollviews that add UIViews as subviews. For the type of UI I'm looking for, storyboarding really doesn't cut it.
And as badly designed Game Center may be, I have been playing Letterpress all day on it with only one hiccup. It can't be _unusably_ bad anymore on iOS6. The author of Letterpress found nice words for it too[1].
[1] http://www.cultofmac.com/197905/tweeties-creator-has-a-new-i...