Let's be honest; slapping the word "gourmet" on something doesn't make it any better than it actually is. GBC offers over-priced run of the mill burgers with no frills simplistic branding (which I dig). I mean, the burgers are decent but I've had better. On the plus side, their fries and onion rings are money in the bank!
Also, seating is quiet limited so consider yourself lucky if you get a spot during lunch hour. Eating on a Cabbagetown curbside isn't usually that fun.
In the end, it's a viable burger option if your in the neighbor but nothing to write home about. Seth Godin was right, marketers are liars because there's nothing gourmet about GBC.