It's something like a bizarro-world version of Bartley's Burger Cottage in Cambridge. Replace cramped and friendly-with-your-neighbors cafeteria seating, absurdly decorated walls, and traditional eccentricity with sleek, efficient, trendy, and modern (and expensive), and you're on the right track. The common thread though is the narrow focus on doing a simple thing ridiculously well, in this case burgers and shakes (we New Englanders would call them frappes, of course).
Even though BLT's attention to detail seems borne of clinical efficiency than family-run tradition, the end result is still one of the best burgers & fries i've had.