I tried those 15X eyepieces...
I tried the 15X eyepieces in my stereo microscope:
http://www.greatscopes.com/achi.jpg
Which gave me 15x and 45x magnification. But, it wasn't an advantage. The most noticeable difference was field flatness. The straight edge of the razor is only straight from edge to edge of the field of view if it cuts the center of the view. Otherwise, it appears to curve. Annoying. I put the 10x eyepieces back in.
At 30x, the width of the bevel is about one seventh of the entire field of view.
I had a look with my high powered microscope today, at 100x, which I hadn't tried before with an edge I have honed.
The view was good, and the results very similar to what you showed us, Robert. But the problem with such high magnification is that it takes forever to inspect the entire length of each side of the razor.
I think it's most useful in looking for any light reflected off-angle from the edge itself. I could sure see flat spots after the first time I tried honing my razor. The effect was startling. In contrast, an edge with no flat spots is just about invisible.