I do them somewhat regularly, through the agency I work out of in St. Louis. I tell you what, working those hotel ballrooms on Michigan Ave. on a Saturday night is the schlep equivalent of a mountain climber tackling Mt. Everest.
One of the coolest things about being able to do a gig like that with my small Thunderchild cab on a small 'luggage style' cart is that you can get away with 'front door load in' sometimes, and also on the rare occasion where I stay in the hotel that I'm performing in, you can just wheel the rig to your room after the gig. Nice!
New York gigging schlep, of course, is a whole other thing that I can't quite imagine

The New York scene was Duke's primary motivation/inspiration for developing his original cab, the Thunderchild112 (based on a few conversations a couple of years ago). Deep and loud enough to do a pop dance gig, sensitivity (given the custom 4ohm 3012LF) high enough to get full performance from a 500 watt micro head, tonally EB friendly and DB friendly, and small enough to fit in a cab trunk, on the subway, or a long walk on a small cart!
These small 'super cabs' really are wonderful..... no tonal compromise and little 'volume' compromise, and just a dream for the 'self employed freelance player' that always has a 'solo load in and out'.