We have 2011 Mountaineer. Yes we are happy with it. There are things that I wish Keystone did different, but it works out all right. The only real trouble we have had was a bad hydraulic ram for the bedroom slideout. Dealer replace under warranty, other issue was a crack in the table, again replaced under warranty. As for cold weather we have used it into the low 20's. Use electric heaters and a 100-watt light in the storage bay. Once the trailer has been kept warm we don't need to use the propane furnace to keep the plumbing from freezing. I don't think that I want to go much below 20 though.