I would choose Plaza, but I've had great experience in both. I've had the burger and the Kitchen Sink at B&C. They have the best burgers on property! I didn't enjoy the Kitchen Sink because most of it turned to mush, but the other sundaes etc looked great.
Plaza is amazing! Their toasted sandwiches are sooo delicious, and their fries are too! I have never had great service in the Plaza, but the food makes up for that. For dessert I had cheesecake which was wonderful, and I enjoy the theming of the restaurant too.