Is Class A smoother ride then Class C and MPG

Met a couple that had a class C that they said rode like it had no shocks at all. So I crawled around and looked to see what I could find. The air shocks factory installed were full of water, giving the rear shock zero movement. I have to guess someone added air that had water in the air compressor and instead of air, they got water. Took a while to flush the water out, but once we got air in and took it for a ride, they said night & day difference. My class C rides to me, very well and is comfortable to drive and ride in. I carry the correct air pressure for our weights.