Personally, I would never buy a 4X2. I have had too many situations where 4X4 saved me - not necessarily from being stuck, although that has happened, but saving my grass where I park my 5er at home. A number of times, I went to pull my 5er out only to blow traction in the back end because the grass was a bit wet. If I hadn't had 4 wheel drive, I would have chewed the daylights out of my grass. Put in 4X4, though, and the truck walked out of there like it was nothing.
I always put my truck in 4X4 when towing a trailer and I leave the pavement. It doesn't have to be boondocking, just loose gravel, sand or grass.
My 2 cents worth, anyway.
Bert