Hu billy. It all has something to do with how the camper is attached to the chassis or maybe how the leg bone connects to the foot bone. Folks on this Forum are very fond of being exclusive but yours is a good question and deserves an answer. We had a Class B (Roadtrek) and it rode like the big, heavy dodge van that it was. It rattled and banged a lot but we loved it. We now have a B+ (or C-), built on a Mercedes Sprinter chassis. It has a smoother ride and much less noise but still not as good as our GMC Sierra Truck. We love it too. We rented a big Class C years ago and it rode like a tank. We did not love it but maybe they are more comfortable now. Can't speak for a Class A. lizzie