I have taken quite a few classes at a local store and have learned from them all. I have never had a truly bad instructor, though I have had two instructors, who were definitely card-carrying members of the quilt/sewing police, and could have lightened up a little bit. The classes I've enjoyed least are usually due to one or two fellow students who are extremely needy. Some people need to fork up the dough for private lessons.
I'm taking a class next week on hand applique. I'm self taught using books and the internet, but am embarking on an ambitious project this month, and want to an opportunity to ask some questions. Hopefully the instructor won't mind that I am really interested in the technique only and have no intentions of finishing the entire project. She has very specific color requests for fabrics (no way am I buying new fabric for something I won't finish). Hopefully she is laid back!