Yep, gotta be honest here.
When I am not in an application, I don't get the fast rotate any longer. When I turn the iPad's orientation, it takes a number of seconds for the screen to rotate also.
I think it's because I've installed InfiniBoard, InfiniDock and EnhancedFolders. So, the iPad has to flip/re-load (re-draw?) all the icons in a configuration never designed by Apple, so it takes a bit longer. At least, that's my thought.
Does it bother me? Yeah, a bit, but the trade-off is 500X's worth it. So, I'll wait for the board to flip...
Now, inSIDE the applications, when I've got something running, or calling up the app (to make it start), there is zero hesitation. In fact, I'm with Demandarin up there in that I'm running FakeClockUp, which does speed up the graphics.
Since I am able to use gestures to switch apps, I can move between apps with ease. Plus, if I need to, with one virtual button push, I can remove all backgrounded apps and free up memory.
I can't comment on battery life because I plug it in nightly. But, I can use it all day without needing a charge - so I don't think battery life was affected.
P.S. If you don't use the search function and do research and due diligence, you're going to miss out on a lot of insight and good comments. It's how I got the nerve TO jailbreak. Basically, I wouldn't recommend relying solely on the inputs to one thread. I'm just sayin' ...