It's still not close to as good on iPad 4 as it is on iPhone 5, that I can tell you for certain. It seems stable, but you notice the lack of attention paid to the frame rate when you pinch to return to home.
It drops several frames and, frankly, suggests that the animation should be simplified on iPad. Just have something less fancy take its place. For example, it's fine when you use the home button, so have that animation regardless of what you're pinching out of.
The App Store isn't fantastic, either. It's better than it was with the last beta, but it's still laggy for a few seconds on launch, and if you go to an app and click on the screen shots, you'll notice the low frame rate for the first swipe or two. Not something that happens on the phone.
Rotation of the iPad is the other one that stands out - skipping frames. It's all cosmetic stuff, but does suggest a relative lack of pride and focus in the tablet version. It feels a bit Android 2011 on iPad, whereas iPhone 5 is brilliantly smooth.
