Thoughts on Kohetsu knives?

I just got a Kohetsu hap40 petty and I love it, it holds an edge like no other knife I've owned, nice profile too. Anybody try any of the other Kohetsu knives? Who is the blacksmith?

It's a house-brand... so most likely the different lines in all kinds of different steels are from different makers / manufacturers. No clue who actually makes the HAP40 stuff; have seen similar looking knives sold under the brand 'CoSay' (cleancut had them at some point) but I think that was just a brand name as well.
It's not too surprising it holds an edge well; HAP-40 looks like a pretty badass alloy.

I find that hap40 has brilliant edge retention related to board use but it loses the razor sharpness over time (whether used or not). It's semi-stainless and quite high carbon, so I wonder whether there is slow micro corrosion at the edge?

The main reason I don't use them (mine are Gihei) a lot is the thin flat grind (poor food release). For me, profile, grind and HT are more important than steel selection in determining the utility of a knife.

Initially I thought that Gihei was making the Kohetsu HAP40 too, or maybe an initial batch, but now i am not sure

Your right the razor edge seems to fade but it holds an edge right below razor sharpness for a lot longer than my blue 2 yoshihiro, my Kurosaki AS or Fernandez 52100. I use it for much longer between sharpening sat work. Hap 40 is amazing