While I've never owned a Montana, I've always considered them a good choice in their price range. Seeing them from the outside, in various parks, they appeared to me, to be a cut above most other mid priced FWs.
My Yellowstone Canyon Trail FW was advertised to be a 4-season model. After buying it, moving my stuff from one FW to the other, 250 miles from home, I needed to camp 20 miles from selling dealer. It was 10:00 pm, a dangerous severe storm approaching. I was amazed how quiet this new FW was, compared to 3 previous RVs I'd owned. It was very well insulated throughout.
Just 2 weeks later, I'm camped at 6k feet and overnights in the low 20s every night. Again, I was amazed at the quietness inside, and how easily it heated. I knew from inspecting upon purchase, that freeze proofing was well thought out. The heat ducts followed the water lines through the cupboards, and in the basement. The line from fresh tank to water pump, and beyond had a heat duct running right next to it. Of course an actual heat duct (smaller) emptying into the basement tank area, which was also insulated. I think my FW could handle an over night temp of near 0, but I will never find out.
Anyway, just my experience of a not so much talked about model, the Yellowstone Canyon Trail. At the time, this was the upper end of Gulf Stream products, but being manufactured in it's own Yellowstone facilities.
Jerry