Do they get massively busy? Yes. Why? They're worth it. The wait usually isn't that long once you get in. This isn't fine dining so I don't understand half the complaints found in the other reviews. Their food is tasty, cheap, and filling. My husband and I have tried their chicken burger combo (for $5, half of what you would pay anywhere else for sandwich, fries, and drink), cheeseburger, and chicken slouvaki on pita. Everything was delicious. The chicken looked like it could have been one of those frozen chicken patties that they quick fried but for $5 I won't complain.
I highly recommend the chicken slouvaki on pita made all the way with the lemon sauce.