We have the double-glazed, solar
reflective windows in our TT and they are nice. They do cut down on condensation as well as adding insulation. However, I don't think their absence should be a deal breaker, if you otherwise like the trailer. Perhaps I would have a different opinion if I were a big fan of camping in subfreezing weather.
I have a question for those of you who have been shopping for a new Bigfoot TT. Do you know the model of the china toilet upgrade they are offering, particularly on the 17.5? The stock one is a plastic Thetford. We are considering an upgrade in our 2004 and are leaning toward the Sealand Traveler Lite. We liked the Sealand Traveler in our 1998 Casita