Well, I can see your beef with your class A rig if driving above 50 mph causes the dreaded white knuckle effect. When shopping for our current class A we viewed/drove 2 dozen units across 4 states over 2 years, whether diesel or gasser, they all did relatively fine at 50-65mph, no white knuckle events, of course this is in fair weather conditions.
When we picked up our Monaco gasser first summer of pandemic a few years ago, we had to drive through record breaking Texas heat back home to NM. We drove the entire way at 65-80mph. Before this purchase I had never drove a 40' long, 13' high, 9'wide, square block down the road (towing 5K# GMC toad) at highways speeds, all things considered it was a pretty smooth and uneventful ride home.
Only issue which significantly affects our ride quality is high winds, rain is no issue, but we experience crazy wind during our Springs here in NM. After hearing your improved ride quality results with installed rear trac bar, it definitely has me thinking of adding one as Springtime is nearly upon us. We still have factory Bilsteins and bump stops, probably get around to changing them out this year too.