[KeithInUpstateNY]

More than craftsmanship, I think it's design and materials. They are engineered for a perfect world. For example the sandwich floors can bear the weight, but are much more susceptible to water damage. One of the reasons I went with the Avenger is it has s 25 year warranty marinr grade plywood floor. It's heavier, but it's going to last longer. And the "fiberglass" exteriors are more susceptible to temperature swings, the entire back wall of my Bullet went wavy after just one winter with temperatures going down to -20. There are brand new units on my dealer's lot with the same problem after one winter. Ideally I'd opt for aluminum framed and rigid insulation with aluminum siding, but no one makes them. And there's some planned obselrsence, I think, with rubber roofs. I still have a 19' 1989 Nomad fifth wheel that has s metal roof and has only ever had one small leak at the antenna. Just my (not so) humble opinion.