My wife updated to the 2.1 OTA software a while back and has had nothing but problems since. Insane battery drain first of all. It will drop from 80% to 20% in a matter of two hours, TOPS. I downloaded spare parts and checked partial wake usage with nothing out of the ordinary (all stats were under 8%). In the "other usage" category, it lists "running time" at over 65-70%. I check my Droid, and my "running time" stat is around 5-8%. She never had this issue before the update. I've checked GPS, Wi-Fi, updates, sync, etc. and it all is either set to off, update hourly instead of 15 minutes. Last night she received a Force Close message from the HTC system program while trying to set an alarm ringtone.
Have you guys had any issues after the update? I think my first stop will be to factory wipe the phone and try to update it again.