Yup! Two. Hartford in 2008 and Manchester this year. It "cost " me both times but oh my did I come back with lots of goodies and ENERGIZED to create.
My favorite classes were by Boxer, Button Farm and Lickety Split. You can read class reviews by searching on the two peas message board, and I think there are a couple threads on this board as well. CK's own classes and Piggy Tales are some of the "less well" liked.
I also did the all day album class in Hartford. We received TONS of product so although it was expensive, I felt like I had gotten my money's worth. However, the Album was "all about me" not a subject I'll ever use.
The crops at night I felt were - meh. I went to the Saturday night crop in hartford and sat with some girls I'd met in class. That was fun, and I finished quite a few class projects but the stupid games and useless giveaways were not and I wouldn't do it again.
Advice:
Don't schedule back to back classes.
READ the class descriptions.
Leave more time and money for shopping than you think you'll need.