what's a medium sized travel trailer to you? The trooper doesn't make for a great tow vehicle and I would say SAS'ing does little to help that (in fact, I'd be more apprehensive evaluating factory tow limits on a modified SAS suspension). if it was me, I wouldn't be towing much more than you average small pop-up camper, say around 3,000lbs, on a regular basis.

-Rob