I'm not sure DRV needs to worry about the Redwood line. I was researching that one a while back because I was asked about them over on RV Dreams' forum.
When I got to looking, I got turned off really quick when I found out that they have a 12" "main frame" and a 10" "drop frame." My understanding is that the drop frame is that section near the front that runs immediately under the basement.
No way I would have a trailer with that section being only 10 inches. While the page at the link below doesn't specify what the frame size is, it does give a fair image of the frame.
http://www.redwood-rv.com/features/f...ted-technology
This link shows their construction details, but fails to mention the frame size. While my looking today has been short and somewhat limited, I'm not finding where they specify their frame size. However, they do say the R-rating for the walls is R9. That's a bit shy of DRV's R16.
http://www.redwood-rv.com/features/construction
Terry