Do you mean the Demco Pinbox? If so, I have a friend who usues one. He likes it but has had problems with the welds. Demco will stand behind it and send out the replacement parts. He also says they believe they have a fix for the problem. Nuwa uses them on many of their trailers. They help solve the chucking problem.
I have an Airsafe 25k hitch and have pulled 10,000 plus miles with it. Works great no problems and don't have to replace it if I get a new trailer.