Application experience can vary widely between the different phones, OS, and UI version combinations. It's ultimately up to the developer to iron out the kinks, but can be such a PITA that depending on user-base, "good enough" is all that's needed. In some cases, it's just plain crappy.
I found iOS app experience to be at least consistent and more polished. I'm not sure it's so much of the OS as it is lack of Apple models and iOS versions to test against. That, and Apple is picky on who and what gets publish in the App Store. Though I will concede that limits consumer choice, but honestly I don't miss it. There are more iOS apps than I know what to do with anyways.