Love the way certain DP owners will tell you theirs ride so smoothly no matter what but only if you have a tag axle and side rad if the truth be known.( so I read between the lines) A newer gas powered coach will ride fine if you have proper tire pressures and your belongings loaded. When we drove our new gasser empty it did ride a little rough on rough roads. Once I learned how to drive it, loaded it and adjusted tire pressure it was fine. Noise is not an issue either other than the odd time we drive steep inclines. Normally the only thing we hear is wind noise but what would one expect with a billboard running down the road.
ps: some day I might have a DP but so far in the 4 years of ownership we could not be happier and still have lots of $$$ which we did not tie up in a more depreciating asset.