I used to be old school and was annoyed when my climbing buddy started pulling out the GPS. I surveyed for the Forest Service in college and thought maps and a compass were the way to go until we got caught in whiteout on N Sister. I am normally a walking GPS but I found that even with the compass I would get off course and completely turned around within a couple of hundred feet and have to reset. The GPS was bomber and saved a lot of time on the walk out.
Now I take the GPS everywhere although I rarely use maps. I pre-mark important points like trail junctions, import previous tracks or waypoints form previous climbs, escape routes like the Pearly Gates and top of the Palmer, and sometimes pull in points from Google earth. And during endless slogs it is a good time waster to check speed and distance and otherwise occupy the mind.
In the field if I feel I might need to backtrack I turn tracks on and occasionally mark things like bivy sites. So to get to the point I love the GPS, carry a compass but never use it and would feel very comfortable relying on it when visibility drops.
Go for it Bill