I do like classes where you're with a group. The social aspect, as mentioned, is always fun. I've taken classes I didn't really need just to meet people.
My dealer does one-on-one classes for purchased machines though - they don't have any room for anything more than that, it's a TINY shop that is crammed full of machines. I like her, but not enough to hang out for 1-1/2 hours to be taught things I already know.
I'm always too antsy to get my new toy home and play! And she probably has better things to do, too.