[rverdlm]

There are so many things that effect the ride that it's almost impossible to know what will help, but here are a few things; First off how much air are you running in your rear truck tires? Weigh the rear of the truck loaded and go to a tire chart and air them up accordingly. Same with the trucks front axle. Does your trailer run level? I always found it best if the front of the trailer was about an inch higher than the rear. The other things like the hitch and suspension you seem to have a handle on. The one other variable is you. no one can know what your personal comfort level is. What I would find exceptable, you might find terrible. All that being said some roads are just plain going to be horrible for your partcular setup. That is because of the truck wheel base plus the distance of the truck axle to trailer axle spacing. This can cause your setup to get in a resenance on certain concrete highways. Then all you can do is slow down until its more comfortable.