Air suspension has been around a real long time. Semi truck with heavy load have used air suspension for years. Sure the compression might go out, but so can other things. I like the idea, I have a 2014 Ford on order and if I had known about this from my Ram dealer who only wanted to sell me what he had in stock I would have given serious consideration to a Ram.
There is a company in Canada that has made an after market air suspension systems to replace spring on pick-ups for several years and those I’ve talked to really like it, take a look.
http://www.autoflexsuspensions.com