We upgraded on Jan 17, 2013
It was amazing how painless the upgrade is. Almost no issues post upgrade discovered yet. We upgraded from 5.2 to 6.0 and it was a 6 weeks of pure pain. We upgraded from 6.0 to 6.2 and a week of difficulty. 6.2 to 6.3 was just as good as it gets. I hope this becomes the model for all future upgrades. We have a few minor issues, but they are so minor, it's not worth mentioning here.
Good JOB DEV!!!