I currently have a Chevy 4WD that I use to haul my truck camper and tow our 5th wheel around the country. Our previous truck was a 2002 Dodge Cummins 2WD and it worked just fine for the 144,000 miles we used it. I decided on somewhat short notice that I wanted to trade trucks before a trip to the mountain west pulling the 5th wheel in the Rockies. Beings that I am not very brand loyal, I was looking for a one ton diesel, crew cab and a long wheel base that was somewhat pimped out on options. Most one tons in this part of Florida are specked out by the dealers to be used as work trucks. So the 4WD unit I found at the local Chevy dealer was the only one in the area that met our needs. Plus they were very aggressive on their pricing and gave me what I considered to be a fair trade in on my Dodge.
The 25+ years I lived in Alaska and the 10 years in western Colorado I always bought 4WD vehicles and used the feature very often in the winter time or hauling fire wood on the logging roads and trails. So to me, if I were to move back to a snowy state, I would keep buying 4WD units, but for my using them now, to haul or pull my RVs, they don't serve much purpose IMHO.
I have found that most of the 4WD units, no matter who builds them are harder on front tires, require more maintenance, get about 1/2 MPG less on fuel. If when looking for my current truck if I had of had a choice of the same truck in 2WD or the 4WD, I would probably have gone with the 2WD, for the way I now use a truck.