We have a 2400. Almost anyone we consulted with about the effects on ride height and ride quality recommended adding one or more leafs to the rear spring set instead of air bags. We had a suspension shop add at a leaf to each side four years ago. We have been very happy with the ride and extra 1.5 in of ride height. It was a relatively cheap and simple solution. There was no noticeable effect on handling.
Hi randallandchris,"Replacing" the rear leaf spring suspension with a full air ride suspension is designed to improve the quality of the ride, making it more comfortable. The problem with these types of suspensions is that if there is a failure with an air leak of any kind, the vehicle is incapacitated.
I have the full Kelderman airbag setup for the rear of my PC. It does help with the ride massively, but also allows me to level the RV and lower/raise it for towing. I also have bags in my front springs.