If you're already using 9.04, I'd suggest waiting. 9.10 has way too many minor but annoying changes and overall, reminds me of why I left Fedora. I just wasted a few hours upgrading today (can the Ubuntu mirrors be any slower?) and now I'll be wasting more time reinstalling 9.04.

Despite misgivings about Unity, I upgraded to 11.04 on Monday night.

Turns out my misgivings were entirely misplaced, since Unity won't even run (just hangs). Shrugging that off, I proceeded to switch to the "classic" desktop, spent an hour fixing all the settings that are required for Compiz to work properly without Unity (moving and resizing windows, etc). I finally got it into a pretty happy state and was set to move on.

Issue #1: suspend/resume broken. Oops. This worked fine under 10.04 and 10.10. Suspend works, resume doesn't. I figured I could figure out a quirk or wait for an update to fix this, except...

Issue #2: an update on Tuesday (not sure if it was kernel, compiz or xorg Intel drivers) seems to have permanently broken my desktop. Now I can only log in using "classic desktop (no effects)" or "safe mode". Fiddled with it for another hour, before giving up.

At the end of the day, I ended up reinstalling 10.04 and then upgrading to 10.10, where things are more-or-less sane again. 11.04 is an unmitigated disaster as far as I'm concerned. I'll stick with 10.10 until 11.10 or 12.04 is released, but if the next release doesn't improve their QA considerably, I'm thinking I'll be moving to Debian Mint.