I have had experience with 2 different models of Trail Air pin boxes. The original L05 model and most resently, with the Tri-glide. The Tri-glide gave us a much nicer ride because, it had the air bag for up and down and the king pin which moved back and forth.
They are not cheap! But, the Mor/ryde pin box is currently on the Pinnacle. I'm going to give it a chance to prove itself. If I don't like the ride it gives us in a few weeks when we head 950 miles south, it is getting replaced with the Trail Air tri-glide.