There's a reason the line goes out the door a lot of the time, other than that there's no room inside for people to line up. The prices here are very good, and the food is quite tasty. I have other Chinese BBQ stores I prefer to get my roasted pig, my char siu, and my roasted duck from, but this is a very decent substitute when I can't make it to those stores.
Why Kong Kee gets the 5 star is because they have a Chiu Chow style duck that is the same price as their roasted duck ($10.50/half or $21/whole) and it's about as close to a legit Chiu Chow style duck as I've ever found in a Chinese BBQ store. Most of them say they have it, but it tastes like soy sauce duck. They even have the vinegar on the side! Whenever I'm craving that duck (basically whenever I think about it), I'm going to come get some.
Fun story. In Chinese, the name of this store is Bald-headed man BBQ. The owner, the guy butchering the meat, is bald.