I never upgraded to Ubuntu 12.10 as I was happy with 12.04. But when I upgraded to 13.04 everything worked fine except for one very little problem and that too it was not Ubuntu 13.04 itself. I faced problem with my Nvidia Drivers. I installed current version and still had a fair amount of lag while opening up the dash or dragging windows across the screen. It was becoming very frustrating especially when I had to do some urgent work.
I know this is driver issue as I did face the exact problem in 12.04, but no sooner I switched to post-release updates (version current-update) driver all problems were gone. I couldn't find the same option in 13.04 so after using it for a week I had to downgrade back to 12.04. I think I will stick with 12.04 for a while.