Sometimes vehicles just feel better with a device installed. When towing our 16 foot
Scamp with the Jeep Wrangler, it is very sensitive to correct loading. If a little tongue
light the trailer will just want to oscillate ever so slightly. If the friction device sway control is used the oscillation is not felt. Like a bandaid it covers the problem. It won't work for big loading errors, so not a magic bullet. The Jeep is tall with soft suspension and big squishy
tires, so amplifies forces imparted by the trailer. I don't see how WDH would help the Jeep as it has plenty of traction up front and computer controlled air bags to carry the
weight. Our new tug is an old 1/2 ton Chevy that has been lowered with firm shocks, springs, sway bars, and low profile wide
tires. Towing with it is extremely stable, as it can resist trailer forces easily. It handles like it's on a rail. We have not used a friction device with it. A WDH is also not needed due to it having air bags inside the rear coil springs for leveling if needed. Front tire traction is not a problem with sub 500 lb tongue
weight on the trailer. Front end weighs 2000lb and rear
tires provide the drive.
Many people that use WDH's probably don't need them, but if it adds to the driving comfort level, why not if it's OK with the car manufacturer. They add a little time to hook up, but not a big deal.
Russ