I went from 1.5 to 2.1 via OTA and have noticed some very annoying issues.
1. Battery life is way down, use to last 2-3 days on a charge, now it only lasts 13 hours. I have made sure WiFi is off and auto-sync is disabled for my accounts. 7 SMS (sent/received) and 1 MT voice call (45 secs) during the day. I can slide through all 7 screens and the battery will drop 1-2% with the only "running services" being "Touch Input".
2010-05-18 Update: The battery dropped 20% overnight (7 hours) while sitting on my night stand. Now the "running services" are "Google - GTalkService", "Touch Input", and "Calender - ObexService".
2. Unable to make voice calls any longer. Never get to the hear the rings, after 30 secs the call attempt just ends. But phone will receive an incoming call in the same location as attempting to make a voice call.
3. When trying to dial a number it takes 3-4 seconds before the number that is pressed to be displayed. Like it is trying to search a very large phone book. I supposedly have 185 contacts.
4. Speed dial locations do not save
5. "Sent Message Successfully" notifications after each sent SMS.
2010-05-18 Update: It seems that SMS notifications (sent and failure) are new with 2.1. See
http://androidforums.com/htc-droid-eris/80279-message-sent-successfully.html.
6. Timing issue with the display lighting up and audio notification with incoming calls and SMS.
I have not had a chance to read through the thread yet, just wanted to get the issue I am seeing down before I forget them. I will read through the thread tomorrow and see what suggestions have been posted.