I have the 4500 Sterling (Ram) 4500. The main difference between this and my last 3500 truck is the weight capacity. They're both duallies but the 3500 was literally AT capacity handling the fully loaded AF1150. The 4500, even without air bags barely notices the camper. BUT, and here's the biggie- you go to 19.5 tires when you get the the 4500 size and those are NOT able to air down for beach use. If anybody has any experience showing otherwise, I'd be grateful because I'd love to take my rig down to Corpus Christi, but haven't for fear of getting stuck immediately.