I just bought a new 5th Wheel. I have had one before and it came with an old hitch (don't recall the brand but it was nothing special). My new 5th wheel has a GVWR of 12,000 lbs - Dry Hitch of 1625....
The pro 15 will work fine but does alot of clanking banging and chucking. We used one for about 1 1/2 years on the same slider. I did recently sell that hitch and bought the Patriot but have not tried it yet. I do have the Reese Revolution pin box so I don't need a slider.