I have the 5th-airborne, but only because I was experiencing a little chucking and jerking on our lovely Michigan freeway expansion joints. It did make a big improvement.
But I wouldn't just install one if you are not having any similar problems.
Keith J, Retired from GM Engineering
2005 GMC Sierra 2500HD SLE 2WD/CC/SB/DA.
1999 Sunnybrook 27RKFS Fiver
Bilsteins, Line-X, Westin steps, Prodigy, Retrax, 16K Superglide, 5th-Airborne pin-box, Multi-vex mirrors.
I replaced a Leland 7910 with a 5th Airborne. The only problem I had when using original holes in trailer and pin box it moved my kingpin forward 5 1/2 inches and down 2 1/2 inches. I had to modify the trailer to get back the 2 1/2 inches as I did not have any adjustment left on the 5th wheel hitch.