The cost is waaaay too high for what you get. Sure, the restaurant itself is clean and well-maintained with nice woods and finishes, but that shouldn't make the food cost double what it should.
The burgers do taste pretty good, with soft buns and fresh ingredients, but then so do the burgers at In-N-Out, which are less than half as expensive. The spicy chicken shack is actually really tasty with a nice crispy exterior and juicy interior, but it's only available certain times of the year. For all of the angst and debate that is associated with In-N-Out fries, the crinkle fries that are served here are nothing special either, and the optional cheese sauce (for a couple of dollars more) does nothing to change that fact.
The shakes are expensive as well, but again the product is not commensurate with the money that is forked over to buy one.
Fuddrucker's holds a slight edge over Shake Shack; In-N-Out is miles ahead.