Being a Californian, I get really excited whenever I see Shake Shack because sadly we don't have all of this goodness out there. I've only been to two other Shake Shacks other than this one (one of which is the one in New York New York on the Strip). Today, I ordered a burger with fries (no cheese) and the vanilla concrete. The burger, although very good and fresh, seemed to have a soggier bun than the buns that I had at my previous visits to Shake Shack. Otherwise, the burger was pretty delicious. I have no idea what that Shake Sauce is, but it is pretty darn good. The patty was well seasoned and very fresh.
Unfortunately, the fries are nothing to write home about. They are crispy and tasty, don't get me wrong, but they are nothing notable. They taste pretty similar to freezer fries. The vanilla concrete didn't taste much different from any regular blizzard/freeze/McFlurry like concoction. A single is pretty small and might not be worth the $3.50.
For fast food, Shake Shack is pretty expensive. But the burgers are so good and fresh that I always come back! The service here is very fast and friendly as well. And a huge plus is that this location is much less busy than the one on the Strip - of course!