In my early days, I have attended a good mix of demo and hands on baking classes. Some were good. Others less satisfactory.
But I ask myself which I prefer. And if someone ask me. I guess each has its own merits. Quite definitely demo classes are cheaper; you get not to dirty your hands and still got something to bring home to enjoy. Hands on classes will expect more of you but you really got the chance to dig in and experience first hand the baking process: this derives more satisfaction for me, and I tend to learn more and faster.
As you can see (with BakinCalf baking classes), I chose the hands on route. But I may get indulge with demo sometimes if the need or mood arises. ; )