I actually commented on this to some FT friends I was visiting in NYC, since I did Shake Shack for dinner and Five Guys for lunch the next day.

Honestly, I was mildly underwhelmed by Shake Shack. Its attraction seems to be that it's a good, down-home burger joint--something you'd see in a small town in the Midwest, maybe--right in the middle of the urban canyon of Manhattan. But honestly, it's not any more special than a typical down-home burger joint you'd run into in a small town in the Midwest--good, but not mind-blowingly awesome.

I actually thought the burger at Five Guys was better than that at Shake Shack, but the ambiance couldn't compare, of course.

Shake Shack has the Danny Meyer name and the park-bench atomosphere going for it, but it's otherwise unimpressive (and IMHO not worth the wait, except for maybe the first time for the novelty).