Been playing with the GM on my iPad3 for about an hour. I did a full DFU restore, setup as new device. Pretty much everything is running much better than the last beta. I was having a lot of keyboard and input lag before in beta 6, that is all gone now, most everything is very smooth and responsive including the springboard/multitasking animations.
The major exception of course is setting a wallpaper. Mine actually locks up for a good 20sec while applying. Really poor user experience and something I am flabbergasted that Apple would just ignore.
Something interesting about blur effects: Gone from Control and Notification Center, but still on Spotlight Search, Dock and the Reminders app. Just seems odd they'd be gone from the rest of the OS, but still in those places. The A5X might be a little under powered for 3D graphics on retina, but it is more than enough for these 2D effects. I totally think iPad 3 owners are being taken a little here.