I got the 5th wheel rails and the regular under bed gooseneck mount. I made a plate that pins to my rails and bolts to the GN plate with a GN ball welded on the back of it. I had to do this to get my trailers off my cab so I can make turns. The ball and plate and rails do get in the way from time to time but if I need to haul something I use a trailer.
Dad has a V-10 F-350 with the turnover ball, I defiantly like it, his bed is totally clear. Only problem is when you get out int the field and go to hook up the GN trailer you gotta reach under the fender and pull the ball lock level. More times than not I wind up grabbing a big handful of mushy green smelly stuff.
Here is what the back of mine looks like
