It would depend, I would like a class on something like a Twisted Log Cabin, which would run a couple of weekends. But I would also like a class on hand applique which would run an afternoon. I would take a class in how to make an organizer or a tote bag. The one LQS with the nasty clerks offer them, but they were so rude to me the one and only time I went in, I'll never go back.
JoAnn's offers classes, I have never attended as it is taught by their staff, who aren't the best trained in short cuts.
I've attended a couple of the quilting guild only meets once a month and the ones I have attended tend to be more of a "show and tell" format. I need to learn something from someone who is equal or supeerior ro my sewing skills.