Let's share my experience upgrading from 2.1 to 2.2 yesterday.
I reside in Singapore, and upgraded OTA when prompted. Using a Legend bought from a local telco. Unrooted. Everything is out of the box.
1. Did not give me Chinese text input capability. Instead, I got a Vietnamese and Thai text input which I have no use for at all.
2. No haptic feedback (even when it has been checked under Settings) when I use the QWERTY keyboard. Haptic feedback works fine when I need to unlock the phone so a mechanical issue is ruled out.
3. The Legend is supposed to have a function under Settings>Privacy>Back up data so that you can back up your whole phone settings.
Called and mailed HTC. Their only useless reply was software conflict, and do a hard reset (after backup of course but the call centre agent nearly got me to hard reset before doing a back up). I have to d/l an app called My Backup (get the 30 day free version) to backup all my settings and data first before I did a hard reset.
Hard reset and restoration took around 30 min. Not 100% restored but my main items are intact. Just got to get my office mail going again. Last wallpaper used is gone too. No lagginess felt. Apps switch quickly like under 2.1.
But, I got back my Chinese text input and haptic feedback when using the QWERTY keyboard.
The Back up data function under Settings>Privacy is not resolved though.
Seems to drain power more quickly but I got to monitor in for a couple more days before I can confirm.