Bought a 2011 31FKDS a coupla months ago and really like it. The only problem we'vd encountered was the bathroom water froze @ 9*. Feel pretty good that it was the only place it froze. I did insulate the storage compartment under the bed and fixed a few areas that let cold air in. If anyone else has any good ideas to add, please put them out there.
We pull it with a 2010 Ram 3500 and it handles very well.
HAPPY NEW YEAR!!