I was finally able to make it to J. Gilbert's and try the crabcake touted by Moe Greene and it was very good indeed. Excellent flavor and zero filler. I'm a little spoiled as I'm in proximity to G & M, Olive Grove and Timbuktu (in the vicinity of BWI airport) which serve some of the best crabcakes around and they are all more than twice the size of J. Gilbert's, for the same price or a little less. Nevertheless, I liked J. Gilbert's version a little better than Timbuktu's which to me has a bit too much mayo. G & M and Olive Grove also have somewhat bigger lumps of crab, but J. Gilbert's was still a very good Maryland style crabcake.
They didn't have the sandwich available at happy hour (the bartender said they have the sandwich at lunch), but the crabcake appetizer (with something called a tumbleweed salad and pepper strips) was $10.50 instead of the regular $12.95 ($24.95 for the entree). The bartender also said the crabcake was the same as the entree version, with one cake instead of two. In the NoVa area, I doubt you'll find a better crabcake than at J. Gilbert's. Thanks again for the recommendation Moe.