Best Pin Box?

I don't know if anyone can tell you what the 'best' is, but 2.5 years ago our trailer was towing just fine with the standard pinbox, but I was concerned when hearing about people having frame problems, so I looked into the different pinboxes, and decided on the Lippert Trailair. I can watch the shock absorber in action in my rearview mirror floating in the truck bed. It holds air very well and use it with a Demco Autoslide hitch.
JK