About as lackluster as BBQ gets. There is nothing at Famous Dave's beyond mediocre. And the service is curt at best, flat out rude at worst.
The food is about 1 step above TGIFridays or Applebees when it comes to BBQ. If you're looking for something more authentic and tasty, I'd recommend checking out Lucille's BBQ. Significantly better food, and far, far better service.