I got this back in April of 2014 so it may be dated. But at that time these were the differences (according to a market comparison). Please don't shoot the messenger.
P.S. The "quality" comparison is hard to believe based on what members are saying today about their rigs.
Montana v. Alpine Comparison
Here are some things a customer will get with a Montana over an Alpine:
Separate Products – The Montana and Alpine have different engineers, purchasing agents, product managers, product workers, plant managers, and are built in separate facilities. Many customers assume because both products are built by Keystone they are basically the same. This is not true.
Construction - The Montana uses aluminum studs sidewalls, floor, slide boxes, front and rear of the unit. The Alpine uses wood studs in the roof, front, rear, and slide boxes.
The Montana has an aluminum studded (2/3”) floor which allows running water lines in the floor to prevent the water lines from freezing up. It also allows the running of heat duct straight through using a metal duct of 12” x 3” vs dryer vent fished through the underbelly for ducting. This moves heat unobstructed through the coach for better heat distribution and fuel efficiency. The top layer of the Montana floor also is a seamless decking. The Alpine uses a laminated floor that forces the water lines to be run in the basement and increases the likely hood of freezing. Also the Alpines laminated floor is more likely to have soft spots.
The Montana has 5 inch carbon fiber roof trusses from edge to edge that provides the same insulation from edge to edge of the roof. The Alpine’s roof trusses are about 1 inch on the edges and increase gradually to four inches in the middle. Not only does the Montana have more insulation but it is the same from edge to edge. The Alpine has less insulation and almost no insulation at the edge of the roof/ceiling.
Upgraded Suspension – The Montana has the Mor/Ryde 4100. This suspension provides 4 inches of axle travel, and has greasable wet bolts, half inch shackle plates, and bronze bushings. The Alpine has an off=brand suspension system with only 2.5 inches of travel. This may not seem like a big difference, but the ability to lift 12.000 pounds up another inch is a huge difference in suspensions. The Mor/Ryde gives smoother tow plus is heavier duty which will last longer and save money over the long run.
Upgraded Hitch Pin - The upgraded Mor/Ryde hitch pin not only will reduce or eliminate chucking but it also slides one and half inches forward and one and half inched backward. This will smooth out the transitions when starting and stopping. The Alpine uses a Trail-Air pin box that does very little to smooth out transitions. This component is an inexpensive pin box that has only a minor improvement over a metal pin box.
Fiberglass – Montana uses a high gloss marine grade fiberglass that is a few notches above the Alpine’s fiberglass. It is double the thickness and has hardening resins in it to be harder and more durable. The better fiberglass is also easier to keep clean and will hold its look longer.
Dexter Nev-R-Adjust Brakes - The Dexter Nev-R-Adjust brakes adjust automatically in the forward moving direction eliminating the need for manual adjustment while maintaining optimum performance and braking power. At certain speeds, this will cut the stopping distance almost in half, making for a safer tow. The Alpine does not have this feature.
More Storage – Montana runs a back of solid cherry wood cabinetry in the slide box over the dinette and the sofa. The Alpine has no storage like this and significantly less storage.
Arched Interior Ceiling – The Montana has an arched interior ceiling that provides a more spacious feel and allow for significantly more head room in the bathroom and bedroom. The Alpine has a flat ceiling that significantly decreases the height of the ceiling especially in the bedroom and bathroom.
Quality - The 70,000th Montana will be built this year. Having people in the plant that have literally done the same thing tens of thousands of times combined with quality materials has made Montana the most dependable fifth wheel on the market. Each of the last 13 years Montana has been the #1 selling full profile fifth wheel. Eleven of the past thirteen years Montana has been the #1 selling fifth wheel in the market regardless of price point or type of fifth wheel. Customers choose Montana more than any other produce because of the reputation for building quality products. The Alpine is a relatively new brand to the market.