I just have downloaded iOS 6 beta wifi for the new iPad and I was currently on 5.1.1 at the time, I shift+clicked check for update in iTunes and browsed the 6.0 ispw file. It took 5 mins max to fully complete, the activation was even much more smoother, it took less than 10 seconds. Then after playing around with Siri (uk), flyover maps and other features such as facebook/twitter integration etc. I noticed that my iPad was extremely hot and at the verge of overheating at the back, then as I switched different apps, it lagged slightly, froze for 3-4 seconds that reverted back to normal state. But overall it's great! And the best things is, as I updated to 6.0, it didn't delete my music and videos etc. whereas restoring does. 