I had a brother with load leveling in an Expedition who loved it except when hooking up a utility trailer with widely varying weight. He was never certain how much to tighten the load distributing hitch. When the airbags went out after 12 years or so they cost more than the vehicle was worth. I don't remember if he sold it as it was or went to the junk yard and got steel springs to put under it. At least on my friend's semi the airbags seem to be fairly standard, readily available and reasonbly priced. It can be done. The question is whether the automakers will do it or insist on gouging the customers every chance they get.