I'm picking up the new beast next week and trying to anticipate what it's going to need. I'm coming from A Keystone Outback, and they left no corners uncut when they built the trailer. One thing in particular was there were huge gaps between the AC duct and the registers, and the ceiling was getting more cold ar that the living space. I had to tape all of then along with blocking the duct after the last register to keep air from going to the end of the duct. I also had to do some serious taping at the return air plenum in the unit.
From what I have seen of Grand Design, I'm not anticipating anything like before but I was wondering if there was anything in particular that I might need to look at. All in all, it looks like a great trailer. I went to a RV show two or three years ago with a buddy and fell in love with the first GD I looked at.