OK...lets say your camper is a 4500 lb monster like a Lance 1191 or an Arctic Fox 1140 or a heavier Eagle Cap 995. You may get off the pavement to camp but you aren't going to do the Whazoo with it. ...
So far the Ford LS with 4 wheel drive has been fine. The GM locking axle is obviously better in horrible conditions.
An advantage of 4 wheel drive is the front set might be the ones with better traction. Also, I prefer having my front to be able to steer in really bad conditions. Basically, the same 4 wheel drive rules apply.