I've seen these threads here as well as another brand dedicated site I frequent. To date, two relatively new fivers and two relatively new Ford Super Duty pick ups, only experienced a moderate chucking in the current truck a couple times when one corner of the B&W base was too loose in the Ford 5th wheel option pucks. This leads me to believe that much of the chucking folks experience is due to looseness in their hitch or flexing somewhere in the hitch mounting system. The B&W mounts pretty solidly, no rails while most if not all of the others use some sort of rail system. The air or whatever cushion hitch softens the impact so you don't feel much or very little rattle or chucking. Then there are loose hitch jaws that may contribute to that motion. Of course this is only conjecture on my part, but something to look at. As far as a 'soft' pin box - if nothing else, they will ease the load and lessen shock to both the 5er and to you and the TV - and something I too would like to add to ours.
Dave W along with my DW, Susan and our poodlepups, Callie & Molly,2011 Ford F250 6.7 CCLB, 5er Hitch Option w/B&W Hitch,,Ride Rite air bags, 2014 Montana High Country 343RL (38')