Jack-
Sorry, I was waiting to hear a size of interest, and then lost track and never followed through.
Paul-
I have used asian chisel sets in my Greenlee 228 autofeed mortiser for probably 35 years. I was immediately sold on the better performance of that style both in softwoods and hardwoods, with the caveat that the auger in the 1/4" sizes is too thinly proportioned for dense hardwoods such as w. oak, maple, and harder woods; and tends to tear the head off, resulting in a split chisel as the machine continues to feed.
I've even used them to mortise HMWP
So I have little doubt the Japanese set was a superior performer.
That said, your test procedure sucks, and could be perceived as intentionally biased.
If you intend to give a fair test to edge tools, they need to be working in the exact same substrate. You used a fast grown tough grained plank for the clico with alternating thick layers of very dense and very soft wood; and a nice, old growth, close mild grain board for the NH.
The early mortises are not shown, but in the late section, the clico was clearly plunged through a knot several times, and may have been earlier on the other side? There is no evidence the NH was subject to a similar event(s)
Ideally, the test procedure would have used one board, and alternated cuts in it with each chisel. Using 2 boards with such different grain structure as shown would have been even more interesting with alternating cuts by each chisel.
I think for many of us, the question would be how different asian chisel sets stack up against each other. So far, I have not seen a big obvious difference between cheap sets, and the more expensive ones. IOW, are there ones to avoid, and are there ones that are clearly superior in some way that I have not yet noticed.
There may be some NH chisels in my shop, thought I got them at Grizzly in Muncy, but will have to check labels tomorrow. According to NH site, Grizzly is a US dealer, but if so, the ones I stocked up on were on the remainder table a half dozen years ago. Also, Grizzly closed out their Muncy operation this past fall.
Nakahashi Seisakusho Co.,Ltd / HowToBuy
smt