Unique spot. You stand in line and they cook your burger on a grill to order. You then order your sides (fried zucchini, mushrooms, onion rings, fries, etc.) and pick them up on your way to pay the cashier. Be sure to bring cash - it's cash only! Once you check out, you put all your toppings on your burger in a buffet with all the fixings. You can pick your own table to dine at and sit inside or outside.
Food was pretty good although the burgers didn't have a ton of flavor to them. Service was also good and I appreciated their attention to detail. For instance, the bacon on the burgers is in a circle so that each bite gets bacon. They're also constantly refilling the toppings on the buffet. Homemade root beer was great, but no refills. They offer all the burger toppings you could think of, trash cans throughout, misters if you're sitting outside and need to stay cool, and even a free parking lot - which is pretty unheard of in downtown Tempe.
I'd return because the old western decor and concept are pretty cool. It'd be a fun place to bring a large group as long as you warn people to bring cash. And I can see kids loving this spot too.