Escalade/Tahoe/Suburban suspension upgrades

BenK... I had the rear shocks replaced at Firestone before I drove out from Ohio to Arizona. I recall they had to get the shocks from the dealer, and they weren't cheap. The whole "Air Ride" self leveling system has always been dubious to me. My back end sinks considerably, even with load balancing, with a ~600 tongue weight. On my way out I saw another Escalade towing a much smaller travel trailer than mine, also with load balancing bars, that was bottomed out even worse. I pointed it out to my passenger. Mine really isn't bad. I sink a little less than 2" in back and rise about half an inch in front. But I have never noticed the air leveling that is supposed to be a feature on the Escalade do anything practical for me.