I was very frustrated with my Eris after the 2.1 update. The dialer got worse, it would freeze and randomly "reboot" showing the HTC logo for 20 seconds or so, and then come back up. There were other misc. things going wrong with it, too. All of that finally pushed me to root my phone, and now I love it. I figured, "what the hell.... it's already sucking. If I screw something up by rooting, I'll just get a new phone."
With the 1 click root, it's so easy. I used Titanium Backup to re-install my apps and preferences, and switched to using LauncherPro. I'm still fiddling with it, but I have to be honest, I LIKE fiddling with it. So it's probably not as big a deal to me.
I totally understand the frustration, though. It's an expensive bit of technology that should just work. I like the Chevy analogy... Except for me it would be a Colt Turbo : )
Good luck with whatever decision you make.