Ram offers an air ride system on their 3500, but as far as I know they haven't actually started shipping any with it. The 1500, has a different coil spring/air ride that's been out a few years. A lot of discussion/anticipation for the 3500 system. So Dave, guess there is no real answer to your question!
2015 Carriage RL40, Residential Fridge, Onan 5.5KW
2014 Ram 3500 CTD, DRW, Aisin