There are routes that I have done by ski that I would never have been able to climb, regardless of slope, as it was the contour of the exposed rock that differed so much than when the same area was covered by snow. Dana is an example of a hike changed by snow: a straight up walk to the summit when covered by snow -- a miserable dance with scree when done in the summer.
I agree, Fish, that the narrow areas are far more tedious than the wide open steep areas, as it limits the aility to negotiate grade by traverse. I took the time to become an expert side-slipper, so that while my more aggressive buddies could out-ski me, they could not out maneuver me when the track became narrow & technical.
