Thanks Bruno for the suggestion. My inexperience is showing.

All three razors have been test driven. The two from Doug have the weight and proportions I was looking for and I am very pleased (54 & 56 grams) while the quite nimble Spartacus weighs in at 46 grams. All three are very close in sharpness. The Spartacus is probably the least hard, followed by the M4 with Doug's standard low alloy carbon steel probably the hardest. When I have an opportunity I will get them checked on the HRC scale.

I could not tell the difference between the M4 and the more standard carbon steel in feel or closeness. All three are less than perfect in sharpness and polish, with a bit of pull while cutting. If that is mostly due to polish they might improve with a couple more shaves and stropping's. The Thiers-Issard felt the sharpest, probably due to the more acute edge geometry, but actually gave me more difficulty cutting at my chin than the heavier blades. Despite that it felt a little smoother, perhaps due to being a little less hardened and more responsive to the polishing and stropping than the other two.

Normally I would have gone back to more polishing or fine honing as required to get the best shave I could out of each blade. I chose instead to judge readiness by the 63x view on my microscope alone for the sake of simplicity and comparability; not only to help remove bias but keep the edge from getting rounded by more polishing/stropping which lends a softer feel but less shaves. Part of this process is to keep a running count of acceptable shaves and then the time necessary to return the blade to an equal or superior edge. I will get back when there is a noticeable difference from these initial impressions as the rotation proceeds.

Thanks again for everyone's comments and patience.