Since this discussion is about GN and not 5th wheel, I can answer for GN. To say a GN renders the bed almost useless is an exaggeration. We have a 6 ft bed and there's plenty of room around the ball and the post coming down from the trailer to put stuff. As long as you keep in mind the post has to rotate it's usable. Obviously, with the post in the middle it restricts the size of what you can carry. So if you want to haul a trailer full of stuff plus 4' x 8' sheets of plywood, or need a bed cap/cover, etc., a GN isn't for you.
