I agree that the flexible layout approach is pretty nice (and obviously we're seeing Apple move towards this direction with autolayout), but I'm not a big fan of the fragment API. They sounded better in theory than they've worked out in practice, IMO.
The inability to nest fragments in other fragments makes doing certain things like fragment based tabs or viewpagers rather awkward. And since the fragment lifecycle almost but doesn't quite match up with the activity lifecycle, some extra careful bookkeeping is required to make sure state is transferred properly upon rotation since the entire thing gets destroyed and recreated.
Anyway, the biggest problem for me on Android is that although the new APIs in 3.0 and 4.0 are pretty sweet, I can't use most of them due to having to maintain compatibility back to 2.2 (Froyo). ActionBarSherlock and the compatibility library help a bit, but it's not quite the same.
Which APIs specifically are you missing that aren't in the compat libraries? I agree that Google should be putting in more effort here and not leaving it up to a third party to come up with a backported action bar implementation but so far I've had pretty good luck with the compat libs.
I also agree that there are some rough edges in the fragments API but it's nothing like the mess that view controller containment is on iOS.
The inability to nest fragments in other fragments makes doing certain things like fragment based tabs or viewpagers rather awkward. And since the fragment lifecycle almost but doesn't quite match up with the activity lifecycle, some extra careful bookkeeping is required to make sure state is transferred properly upon rotation since the entire thing gets destroyed and recreated.
Anyway, the biggest problem for me on Android is that although the new APIs in 3.0 and 4.0 are pretty sweet, I can't use most of them due to having to maintain compatibility back to 2.2 (Froyo). ActionBarSherlock and the compatibility library help a bit, but it's not quite the same.