Then again, around these here parts on I90 in the winter, you see WAY more 4wds in the ditch, on there roof, side etc than 2wd's. I seem to recall getting in a wreck in mid january at denny creek. I was the first rwd to take out a 4wd per the leo at the scene!! Could not decide if that was a compliment, or a complaint!
Either way, 2wd works if one is careful, 4wd works if one is a bit less careful, but as sorta kinda mentioned, If you LOSE control, or get stuck, or other wise, your in a REALLY BIG world of hurt with 4wd vs 2wd! Then 2wd with a decent posi can be just about as good, or better depending upon circumstances than a 4wd with both diffs that are open. 4wd with a locking rear is better than 4wd with open diffs/rwd.........
as said, get what suits you. Not sure what my next truck will be.....4wd or rwd with a posi.......I've gone a lot of places with my current dually, previous sw 3500, both with the GM G80 locker that I could not go but in 4wd with my 88 no locking rear in rwd alone. Including a day up stevens pass where chains were required in 2wd, did the same on white pass one time too! Those are 4-6% grades IIRC to boot!
Marty