Did you upgrade or format/install? I'm pondering it now. I've had quite a few system hangs lately and am wondering if I should even attempt the upgrade to 12.10
Did an upgrade cycle from 10.04 through 11.10, installing every release. Did a clean install at 12.04. Have upgraded that to 12.10 and now 13.04. I will not say there were no issues, but I never faced data corruption or unable-to-boot issues during this time. What I did face though was random errors and broken packages. But I did not document those erors, so I cannot go into any specifics.
I upgraded from 12.04 LTS and I had a few niggles - the configs for Compiz were messed up and the AMD proprietary driver wasn't working, oh and grub got nuked.
Ultimately, blowing away the compiz configs (rm .compiz*), a dpkg --configure -a fixed the AMD driver and boot-repair from a Ubuntu LiveCD was a wonderfully simple way to redo grub.
Not painless but not particularly difficult to fix.