My Wife has towed my TJ several places with her '20 Sport S on a fairly light car trailer (1200lb), 3.73 Axles and 37's so far from ideal for the job. Total load about 5000lb.
Using a Weight Distributing hitch and a RedArc brake controller, controlling the load is no problem at all.
Performance on the other hand is not stellar. Longest trip was Windrock, about 7 hours with some hills, we let her lead and set the pace, had her watching tranny temps like a hawk, on some of the hills we'd end them at about 60mph, and the tranny temps would hit 240 degrees or so..
I think this setup will do the job for occasional towing, but if I was going to use it to tow a lot for loads over 4000lb, I'd look to something more robust.