'Tis good! For a cheap and quick burger joint in Vegas, this definitely exceeds my expectations. Both their chicken burger and the beef patty burgers (Shack Burger) taste great, come out pretty quickly, and don't cost too much.
The line goes fast, don't get intimidated. We had to catch a show next-door and only had about 45 mins, and we made it just in time after enjoying our burgers here.
The burger buns were a little soggy for me, and tasted more on the gummy side. I think if they were grilled a bit longer and were crispier, I would have enjoyed it more.
Try out their cheesy french fries - it's a basket of fries with melted (cheddar?) cheese on top. They give you a little wooden fork to eat the fries so your hands don't get too cheesy.