Shaved today using a Robeson Shuredge honed using the progression I outlined in my earlier post.

Killed the edge and then reset the bevel using the Shapton Kuromaku (orange) then refined the edge using the Norton 4K/8K, stropping after completing each grit and finished with 10 light laps on the Shapton Glass 7 30K. I did take Euclid’s advice about using CrOx on a balsa paddle strop before the laps on the 30K. No pyramids or anything fancy, just finish on one stone and then move to the next.

Final stropping was 10 passes on Scrupleworks linen followed by 50 on the leather.

The shave was a comfortable 2-pass leading to BBS. I normally end with Thayers, but instead used my alum block just to make sure I hadn’t irritated the skin with an overly sharp edge. No weepers or nicks or irritation.

Final conclusion based on one shave with one razor: the synthetic progression ending with the Shapton 7 30K produced as good a shave as my regular coticule progression ending with a Vermio. The razor may have felt a bit more keen than my coticule edges, but the shave was comfortable and close without causing any skin irritation.

As far as answering my original question in the OP, beats me. I got the Shapton 30k at a great price and if I didn’t already have the coticules, I would be very satisfied with the shaves I get using it along with the Norton 4K/8K. Along with a bevel setter, that seems a quite reasonably priced synthetic progression.