Lots of people have them. I carried my camper without mods to Montana and back which is over mtns and about 1000 miles. I didn't have to mod, but I did primarily to give tires more strength. A drw wouldn't work for me since my truck was my daily driver. There's really no point for me to buy a drw at this point. I have the mods in my signature.
I haven't weighed my truck with camper in years. The camper is tagged 3571. I believe I'm generally about 12000 if I remember right for a rig that was rated for 11400.
Keep in mind that not all srw and not all drw are the same. I'm certain my srw will out haul older drw 350 or 3500s.
Finally, you can gain more capacity with a gas engine since it is lighter, and a supercab is better for just weight than a cc. The worst is a short bed cc.
