I think all RV manufacturers make incredible claims about their units' insulation values. Think we all get an RV can't be as well insulated as a stick built home. Our fifth wheel was insulated with the Dow Blue Foam in the sidewalls and floor, and fiberglass batts in the attic. Still got hot/cold. And, the recent introduction of the bubble foil in the floors with claims of high R values is only for one type of heat transfer, radiant. I'll be curious to see how our White Hawk does with a single AC unit this summer; I suspect it might get a little toasty.
Like anything in RV construction, it's a function of weight & $$$.