I myself put froyo 39 on it and it was running fast but has slowed down. i had to take some things off it. and i can't get a camera that works decent on it. the regular camera freezes as others have suggested and I have to hit the home button. I have tried out some other camera apps without much success. It's annoying because I was hoping for a decent camera!!
Glad I found this place! My wife's Eris is running the 2.1 update she got OTA, and she has nothing but complaints(mainly the camera is slow, and the 'shutter' seems to stay open too long making most photos blurred). She just didn't want me to root it for fear of something going wrong. She's eligible for an upgrade soon, though, and I think I'll take her Eris once she upgrades. (I've got an extremely buggy enV Touch).
I'll definitely be looking into the xtrSense and xtrRom's when I get it.