It's a digression (and an apples-to-oranges one at that) but your experience is definitely not typical. I have a Samsung Epic (Sprint's Galaxy S variant) running their new EI22 Gingerbread stack (very likely the same userspace base you have). And I don't see this at all. I don't use the built-in mail app, preferring K9. And I don't use the default home screen (Launcher Pro is just plain better). But the transition to the home screen is always instantaneously animated. Certainly nothing like 2 seconds.

So I'd put that up to a plain old bug (albeit a really frustrating one, and knowing the Android ecosystem one unlikely to be fixed), not a platform misfeature.