Yeah, the Dock has frozen up a couple of times for me, but not too badly, Safari crashed pretty hard for me once, too. I did an import of my data from my Panther partition (after an erase and install) and that worked very well. The new Tiger fur desktop pic is sexy as hell, too.
It's starting to feel pretty polished to me, but I still haven't done much serious work on it. I usually go back to Panther for that. But yesterday, I went through an entire team meeting for a class (~2.5 hours) working on Tiger, and the only things that happened were the Dock hanging, and Safari crashing.