I used the little known and now defunct Gene McCall Airglyder hitch with a Binkly head and both vertical airbags along with fore and aft airbags.
That thing was a veritable dream and contributed to a much improved towing experience for the trailer and contents. The Trailair suspension on the other hand needed a complete rebuild due to metal to metal contact of pivot shafts without any grease points.
I was also one of the very rare individuals using a Trailair pinbox in concert with my air hitch and like mentioned above, kept it at 85psi for levelling. Study showed the hitch doing most of the work while the pinbox only moved during extreme whoop-d-doos as found in those flood drainage gulches in Arizona.
That pin box also had metal to metal contact without any grease points and after replacing the bronze bushes once, I rectified that by drilling and tapping for a grease nipple accessed from the rear of the pinbox underneath the top frame of the pinbox.