I saw one being used on a large utility trailer behind a lube truck. It looked like it was doing its job while rolling down the interstate. I know the rear suspension of the truck doesn't flex at all so the hitch was cycling pretty good up/down but looked as if it was making a smoother ride.
2005 2500 Cummins/48RE/3.73, QCLB, 4wd, BigHorn, Edge Juice w/ CTS + Turbo Timer, ISSPro Oil and LP pressure gauges in cubby hole, GDP 20/2 filters on frame rail, Custom Diesel Steering Box Brace
'10 Forest River Shockwave Toy Hauler 21'
Honda EU3000I Genny
I've used the AirSafe hitch for the past six years, which also has airbags for a smooth ride. My Class V AirSafe does allow for weight redistribution when it is needed. It does cost more, however.
We have the Airsafe also. makes a huge improvement in ride on rough roads and works fine with WD setups. Spendy so IMHO it only makes sense if you travel a lot. Ours is either the Class VI or VII, whichever has a 2.5" stinger for my Class V 2.5" receiver. Only downside for us is the weight. The Airsafe is around 100lbs with a WD head on it. I have a small harbor freight roll around moving dolly to move it around after I take it off.
2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2004.5 Silverado 4x4 CC/SB Duramax/Allison
The tongue mount hitch allows for weight distribution.
2002 Chevy 3500 DRW 8.1L/Allison
2000 Palomino B1500
...and the reason why I need a DRW to haul a Palomino:
2004 United 7x14 tandem axle enclosed toy trailer
2011 PJ 8x20 7-ton deckover equipment trailer