We had a Class A gasser at one time, and we would comment how the wife always thought she riding over the top of the guardrail instead of next to it, and we could measure the windspeed by how far the dashboard was tilting downwind :E
All that, and the rattles, went away with 5er. We have to force ourself to watch in the mirror to see how the trailer is doing in the wind, because we don't necessarily feel it in the truck.
The ride of Class A was much smoother than the truck, and when the 5er is disconnected, the truck rides like a lumber wagon.