Setting at 11K, we run 60lbs in the front and 65lbs in the rear with 60-70 in the airbags. Anything more and it's like riding in an old lumberwagon. Ouch.
Also check to see if you have airbags on your axles. If so, they may be inflated to the max, which contributes to the harsh ride.
Another issue for us was the rattles, rattles, rattles. I've found a number of things that made a lot of noise - an improperly mounted microwave, doors that don't pull down tight, blinds that rattle, up or down, mirror doors where the mirror floats in the frame, and so on. Even wall panels that's not properly anchored to the studs (if you want to call 'em that!).
Ours is pretty quiet now compared to when we took delivery in 2010. Most if it costs little to nothing to fix, just time and someone willing to find the rattles while underway. Start with the most annoying and work from there.
Good luck!
