Yes, we have experience towing a fifth wheel with a half ton pickup.
Our set up was a RAM half ton with Hemi engine and 3.92 rear axle rated to tow 8900 pounds. Our fifth wheel was (is), a Flagstaff model which has a dry weight of 6200 lbs.
We towed it from Florida to Maine, Florida to UP of Michigan, Florida to Northern Wisconsin, Florida to Chesapeake, and to Boone NC.
How did it do? Pretty well with Air Bags to stabilize the bed with 50 lbs of air in each side. Acceleration was slow getting on the on ramps if there was a hill involved. What is not often considered is the half tons other weaknesses when towing, namely stopping. Brakes on HD trucks are much heavier, as are the suspensions. We kept speed to the 55-58 MPH range on the interstates.
This year we wanted to return to the Western part of our great country, so we traded in the half ton for a new RAM 2500 with the Cummins Diesel engine. We are delighted with the improved fuel milage, the ability of the diesel with engine braking (standard) to handle the mountain descents, and the low RPM as she pulls the hills without down shifting and the steep grades with only minor downshifting.
We made our decision to buy the fifth wheel after seeing a lot of half tons pulling them on a trip to the Canadian Rockies with our 19.5 tag along trailer the year before (2007). They explained that it could be done if you accept their limitations.
Hope this helps.
Ron and Joyce in Northern CA, on our 2 month western trip