Our 24 foot E450 Class C handles great using the door pressures of ~80# rear, and ~65# front ... in the taller Defender 215/85/16E tires I retrofitted on it (six, plus the spare) a few years ago.
HOWEVER ... in the rear I had to remove shock stiffness from the situation on sharp bumps - and add shock stiffness to the situation on gentle bumps and curves - by using frequency selective damping shocks in the rear. This has worked like a champ so as to allow a gentle ride while at the same time using ~80# of pressure back there.
I want a worry-free Class C simultaneous with minimum messing around adjusting parameters, so high tire pressure in the rear allows us to load up the RV with no weight concerns before trips, or when on trips. Our rig now handles identical alone or when towing our boat - regardless of how much we've piled in it or on it. I call it having "chassis overkill" in what's underneath the coach.
