We put 420 miles on the Andersen hitch on our five-day camping trip last week. I alternated setting the compression on the urethane springs at 1/8" and 3/16" compression. Much of the trip was on California 99, which has to be the roughest and worst freeway in CA!
At 3/16" compression, the Honda Pilot and Lance 1575 TT seemed to be locked together as one unit, and rode like a stiffly sprung truck. Every dip in the road and gust of wind experienced by the TT seemed to push and shove the Honda around. Wasn't comfortable or pleasant, and I was constantly having to make steering corrections because of what the TT was doing to the TV.
Big difference at 1/8" compression. The Pilot handled well, like it should, with very little pushing or shoving by the trailer, and felt in control. The Lance handled well without a feeling of being rigidly connected to the Pilot--it handled dips in the road just fine. The feeling of control and balance was much more like the experience of towing my boat, which is an easy tow. My confidence in towing the Lance has grown considerably.
The Andersen hitch is rated at 14,000 pounds GTWR and 1400 pounds tongue weight. My lightweight rig is only using a fraction of the hitch's capability. In one of the YouTube videos on the hitch, it is stated that 1/4" spring compression puts 2000 pounds of tension on each chain. I would like to know how many pounds of tension 1/8" compression creates.
With all my measuring, I have determined that 1/8" compression is achieved in my setup with 1 3/16" bolt showing beyond the adjustment nut. So hooking up is easy--just turn the nut so that 8 threads are showing, then adjust with a ruler and rachet.
BTW, I tried once and my coupler does not open with tension on the chains. I don't recall if that was with the full weight of the tongue on the ball, or not. I do know that before installing the Andersen, that I could not open the coupler unless most of the weight of the tongue was removed from the ball. Going camping next week and will experiement with it.