I have used a single, and double friction control. And am now on my third EQUALIZER 4 point.
IMO, a double friction control has about the same anti sway dampening as either the DC or EQUALIZER. Some years back our resident engineer did the calculations, and they were all very close as well.
The friction controls work well.... And the big advantage they have is that they work independantly from the WD function... This means that the set up can be off a lot, and the friction control will still work.... This is why I recommend it for newbies.
Now the integreted say control hitches are setup dependant as to how well they will work.
Once properly setup, they are easier to use.... But not any better performing that a dual friction control hitch.
Most all of the people that rave about them came from a single friction control hitch... That indeed would be a big difference.
But Dual friction or DC, or EQUALIZER is a wash performance wise.
As for how to adjust the friction controls... Tighten them until the Steering wheel of the TV doesn't want to return to center after a sharp turn. Then back it off a little.
That was in the directions for my friction controls.