and it was totally worth it.
ive had a concrete before but never was there for food. i happened to walk by with the girlfriend and figured we'd check it out. the line got excruciating at the 40 minute mark but once we got our double shack burger (amazing), portobello burger (possibly even better), fries (surprisingly great), and 2 concretes, we were in heaven.
one small side note...in carroll gardens, schnack recently closed. i swear, the shake shack burger was just a larger, better version than schnack's little sliders called schnackies. if anyone has the time and dedication, they should revamp schnack with a better location and improve on their menu and have a shake shack-type place in brooklyn...very similar style of burger.