As with any product line, marketing has a great deal to do with popularity, but even with that said, Montana's - the high end model - appear to be very popular with satisfied customers. When we were in the market to buy a fifth wheel, we looked closely at the Montana and they were quality built. For us though, we went with the Heartland Bighorn comparably built but with a few more features that we wanted. And like someone here said, most comparably priced (higher end) units will be better built, as has been the case for our Bighorn. I would suspect that the reason you see so many used is that the owners upgraded to a newer model of Montana or larger one!