Patrick,
It is very crude, but it distinguishes very clearly between an almost sharp edge and a sharp enough edge. For purposes of this project, sharp enough means taking an intact (albeit small) shaving off pine end grain. Yes, I push slowly because I want to see how much deflection I get before the thread breaks. Its main deficiency is not the lack of a peak reading, it's the need for me to hold the blade steady so that I don't slice. This is great fun to think about, but so far it won't replace the copy paper test. And, like Andrew, I will try to resist another $150 toy.
What I really want, BTW, is a way to quantify how much steel worn abrasive film can remove
Doug