In general, air hitches / pinboxes help the ride in the TV and do fairly little for the trailers ride. Something attached to the trailers axles (centerpoint, shocks, EZ flex, etc) help the trailers ride, but don't do that massive improvement for the TV.
With My truck and trailer, side to side rocking of the trailer can barely be felt in the TV, front to rear rocking of the trailer gave me whiplash in the drivers seat. My Air pinbox all but eliminated that, and the centerpoint (in my opinion) should make the trailer last longer, as the frame and everything aren't getting the doodoo pounded out of it driving down the road.
