I did QSFB at Pizzafari for the last Spring Advantage program and I loved it, even though it was definitely hard work. The best way to describe it, I think, is that you will be one piece of a complex and well-oiled machine. You can get assigned to high guest interaction assignments, such as bussing (sorry-- dining room attendant!), cashier, or serving at the counter, or low guest interaction assignments like prep, stocker, or actually making the food (we called this position the Hearth, since we stood in front of a giant oven and shoveled out pizzas and sandwiches). You will likely get 2 to 6 assignments every shift, so you won't get stuck in one position all day.
A lot of people complain about the QSFB role because it is so much hard, hot, sweaty work, and it is in a very, very fast-paced environment, but it can also be very enjoyable. Oh, and my costume was great! It was very light, loose-fitting material like pajamas... very nice to have on a hot day!