Question for the guy's with duallies and big campers

Thanks again for all the input guy's. Looks like dually is the way to go.
My current truck has air bags and I like them, even if one has a slight leak. If I get a truck with a pickup bed, I definitely will want one with the frame mounted tie downs since mine are bolted to the bed and they suck.

A couple more questions if I may.

Why the rubber mat between the bed and camper?

What system are you using to extend the hitch beyond the back of the camper to pull your boats or heavy trailers?