Another vote for Rockwood/Flagstaff. Fully insulated with foam board insulation. Depending on model the roof would be vacuum bonded, or laminated.
Grand Design, Winnebago, and ORV are all insulated with batten insulation in the roof, which I am not a fan. If you do decide on a used one of these models be sure to check for mold in the attic.
Owners of a 2018 Lance 1995
Former 02 Intrigue by Country Coach