IMO - too much. They are owned by the same company so the menus are very similar, as well as the food quality which I'd say is comparable to any other chain restaurant like TGIFridays or something. The atmospheres are basically the same except the rainforest animals are replaced with dinosaurs at T-Rex. If I had to pick one, I'd pick T-Rex because RFC can be found in multiple other cities, so T-Rex is a little more unique.