Yes, I can also attest to changes with adding Sumos and a Hellwig sway bar. After 9 years upgrading a corner bed Four Winds, this past December, the DW and I bought a used 2011 Via 25Q to get away from a low mileage gasser to a high mileage diesel, a more streamlined profile and finally a slide out queen size bed we could walk around and make up without climbing over everything just to tuck things in or go to the bathroom during the night.
With the Via we quickly discovered that cross wind and truck sway was a problem. The dogs were motion sick the first full day on the road. We didn't have this issue with the Four Winds to which I added a Blue Ox stabilizer bar to make towing a 4 down Terrain stop the tail wagging the dog. That's another story but anything on a Ford frame will float the trailer hitch making towing a challenge unless you can stabilize the frame mounted hitch to the rear axle.
Anyhow, after lots of research on the Mercedes 3500 frame and Via suspension I added the black SUMOS to the rear and the Blue SUMOS to the front suspension. I also swapped out the factory rear sway bar for a Hellwig bar. The difference was night and day with truck blast and cross winds. Yes it does ride a bit stiffer and not as soft but it certainly solved the scarry white knuckle driving we experienced those first two days of our stormy trip from FL back to northern KY.
I've had it out several times now; running I-71 from Cincinnati to Delaware Ohio and no longer need to worry about an unsuspected passing semi rolling at 80 mph while I'm happy at 65-70.