"Perspective (personal) huh? "
Quite so diski.
"Steep seems to kick in for me at about 35-40 degrees. My feelings about such pitches - whether I'm comfortable or not - depends on conditions. Powder and springy decrease the sense of caution; ice will heighten my senses considerably."
We share a common awareness. At that pitch of 70%- 80% grade (about the pitch of the steep part of West Face at Squaw Valley) one is aware when the slope is relatively smooth that if one falls, one will slide a long ways.
"Why would anyone use percent grade to describe a slope is beyond me. Isn't angle far more intuitive for most people?"
Because percent grade has been traditionally used to measure inclination travel up or down slopes as highways grades etc. Unfortunately for skiers this has led to a great deal of confusion and misinformation for discussions of slope steepness since most people understand as you relate degrees while the percent grade technical term is usually not. Don't trust what you read in magazines, the media, or from other well known skiers of steeps.
A couple years ago I posted some replies here to others that claimed various slopes were xx degrees steep. The usual comment of many is "that had to be 45 degrees". Very few ski resort slopes have any formally named expert trails with 100% grade sections for more than short distances. The easiest way for anyone to measure this is to stand sideways on a steep slope with ones uphill ski pole resting vertically beside you in the snow. From the position of your hand rotate the bottom of the pole 90 degrees up (perpendicular to gravity vertical). If it is touching the slope it would be about 45 degrees or 100% grade. I gaurantee most will be surprised how far from 45 degrees their 45 degree slope actually was. To amuse myself, I sometimes carry around a small cheap carpenter's angle measuring level one can buy at any hardware store. In the west most such slopes are short sections at ridgelines cornices. An even better way for the sake of nailing your argument is to measure the disputed slope with a topographic map (ie www.topozone.com).
Using a steel rule with 1/100 inch gradiations and tangent tables this can be readily done. A loupe will help.
I'll add one comment to Ryan's. The greater the vertical of the steep pitch the more intimidating. If one were to fall to slides just 50 feet to a runout there is a lot less apprehension versus 500. At many resorts one may find short sections of really steep slope with easy runouts in odd places that skiers tend to avoid. Instead of avoiding them traverse onto them, stop, get familiar with the edgeability, and try cranking a few short dynamic turns without the fear of consequence. -dave