I was lucky enough to get a chance to play around with Marko's 52100 gyuto this past week. Overall, it's a very good knife. I dwell on the negatives for two reasons: (1) I think that's what Marko wants to know about and (2) I think that's the best way to talk about very high quality things. I'd like to thank Marko again for sending this one around (and you should totally put me #1 on the waiting list).
Marko also asked for us to compare the knife to our "best" knife. I selected my Gengetsu 240, white steel, gyuto for the comparison.
MT: Marko shipped the knife sharpened and it had a nice edge. After stropping on some leather loaded w/ 1 micron diamond spray it was piercing tomatoes skins easily. I was impressed how well the steel responded to the strop. I used the knife for around 5 days and while it did lose that amazing sharpness it didn't effectively change how you cut with the knife over that five day span. Very nice steel and I'll be interested in seeing what the pros think of it. The steel isn't very reactive and didn't form a ton of patina under my use.
Gengetsu: The white steel got sharper than Marko's, but it only lasted for a day, if that. If your scoring criteria for steel includes edge retention of any kind, this round goes to the Tsourkan.
MT: I like the grind quite a bit. I tried to take some pictures of it but I just couldn't get any good ones; hopefully someone later on will take some snap shots of it. I think that you couldn't change it for the knife to be objectively better for the entire community. You could trade-off some food release for a little less wedging (it did wedge in some very large onions), but some people wouldn't like that. As economists would say "You're at an efficient point of grind; you can't make anybody better off without making someone worse off." The knife is pretty stiff (not as stiff as the Gengetsu, of course) while maintaining this so props to you, Marko.
Gengetsu: Now, after saying all that, I don't know if I like it much more than the Gengetsu. The Gengetsu has less wedging but more sticktion, so it's a tradeoff.
Slight advantage: Marko
MT: I like it a lot. I was impressed by how well it rock chops and does pull / push cuts. I think this was my favorite part about the knife. The tip is usable and thin without feeling fragile and I like the height. Other than saying it's a good profile it's hard to grade because it's so subjective.
Gengetsu: The Gengetsu has a slightly more rounded nose that gives it a different feel, but is just as effective in my hands. I like it just as much as the MT; it's just different.
MT: It's a Marko. I could complain and say that it would be nice to see a more rounded spine and choil, but I don't know if I would want to pay for him to do anymore than he has done. The handle does have a void but that was mentioned beforehand and it is simply because it is a passaround knife. I would like to say that this is my favorite finish that I've ever seen on a knife. The satin is so even - it's beautiful. I do want to say I think there might be the world's smallest birds beak going on with it, Marko, from your final sharpening. Very easy to fix, but it might be off-putting to some.
Gengetsu: The spine is eased, not rounded, and the same is true for the choil. There's no doubt that Marko's F&F is substantially better.
This isn't so much a category as it is to Marko. I don't like the ferrule. It feels great in a hammer grip but the way I do a pinch grip it gets in the way of my oaf hands. I know you have several options and I could select a different style, but even for this one I would try and round off the edges of the ferrule. Other than that, the saya and handle were perfect. Great in hand feel and work for both pinch and hammer.
The MT exceeded my admittedly high expectations. Nothing I could put in the way would stop this knife with the allowance of two grapefruit sized onions that caused some wedging. I think Marko's knives are a great value at current pricing and are definitely up for the "best in price range" discussion. The score doesn't reflect it, but it surpassed the Shigefusa rather easily in most categories, and in overall score. What isn't clear is how close it is to the Gengetsu in terms of performance. If the Gengetsu was made out of 52100 it would be a real horse race.
9.5/10, Marko beats the Gengetsu