I upgraded the stock hitch set-up on our 5th wheel.

I have been considering a number of options including a new kingpin like a Trail Air or the Morryde rubber pin box to reduce vibrations and chucking.

I ended up going with the Reese Goose Box

Things I liked:

1. Fully approved by Lippert for their warranty on the frame.
2. Overall weight drop of 60-70 pounds vs. stock kingpin and hitch.
3. Reclaim the usable bed space when not towing without awkward hitch removal. Ball and chains pulll right out easily without lifting or tools.
4. Improved bed space while towing
5. Air adjustable and shock dampened.
6. No more chucking (that I can detect)

Downsides:
1. Cost. Around $1200. I should be able to recoup about half of that selling the old Curt hitch and Lippert king pin.
2. Harder to hitch solo (working on a solution to that)

After unboxing in the bed of the truck I shimmed it up.

Using the trailers landing gear I adjusted the height to line things up.