I haven't seen this posted in a while, so I am not sure if any of the newest owners have checked their coaches or not.
On our 2002 I found that the ducting for the cold air out of the roof AC's was sealed very poorly. I opened up the duct under the AC unit and taped all of the unwanted openings. If you search back you will see many posts on this subject.
I noticed that the air flow from the AC's was not that good on the new coach, When I got home I pulled off the AC duct cover plates. I found many openings between the cold air and the return air. I sealed these with metal foil tape and the system is much better now.
2007 Limited SE 40fdts
Las Vegas, NV