My very first smartphone was the Eris. That was the worst piece of crap in the history of phones. I hung on to it, hoping that the horrible lags and freeze ups and crappy syncing on movies would go away, and went past the 30 days. I ended up buying a new Droid on day 33 or something like that, for full retail.
I'm scared to death of touching anything with HTC on it.
My wife hung on to her Eris until this February when the iPhone came out, which I got for her (she's definitely not into rooting, etc.), and she can't believe that THIS is what a smartphone is supposed to behave like.