Karmic Koala upgrade problems

I think maybe I'll wait a while before upgrading my Ubuntu 9.04 to 9.10 (Karmic Koala). If only 10% of upgraders are getting a good experience, I'm just not going there for at least a month. OK, the Windows 7 upgrade took 12 hours to complete, and that was the fourth attempt, but I'd rather multiple attempts with flawless rollback than being stuck with an OS release with graphics drivers issues.