In my experience, a better indication of how sharp a razor is, is the amount of resistance you feel while the razor cuts the hair. You'll have to play around with that and notice that the angle is very important for this, and moving the hair very slowly. By now, having done the HHT hundreds of times, I can pretty accurately predict how sharp a razor is going to be while shaving, though smoothness is of course impossible to predict this way.

As for the non-working link, my link does work: http://coticule.be/hanging-hair-test.html