Firstly, thanks Mert for the opportunity to look at this knife. In reading this, one should note that I am not a professional chef. I have also not had significant experience with a workhorse grind.
I've unfortunately lost the measurements that I made but the knife is long (maybe a touch over 280mm?), tall (maybe 60mm) and heavy. It feels robust in hand. Balance is well forward of my pinch grip. The grind appears very asymmetrical, with mild left sided convexity and very generous right sided convexity (seen from the choil). The spine is thick at the handle but tapers to a very thin tip (as thin or thinner even than many of my thinner knives). The profile is interesting. It's almost (but not completely) flat for the first 70% or so, then curves upward with gradually increasing steepness to form quite a high tip. This results in a profile which makes rock chopping quite easy but without the long almost useless belly that is seen in many mass produced German knives. The blade remains tall throughout most of its length. It is not as thin behind the edge as many knives that I am used to.
The blade is obviously a monosteel 52100 and is finished to somewhere between shiny and mirror. Spine and choil are beautifully rounded. There was an indentation higher up the blade which I thought could have been a result of HRC testing. The handle is octagonal and quite pretty. The ferrule is some sort of black wood and the handle has a beautiful grain which almost seems to move. There are a few tiny crevices in the wood of the handle (Mert did say that he'd made it out of 'whatever was lying around') but the finish on the handle was very smooth. From the Tansu knives that I own, I'm sure that any customs that Mert made with this profile and grind would have perfectly finished handles (my Tansu honyaki deba has my favourite handle of all my knives)
I compared the knife side by side with several of my existing knives over several days (Sakai Jikko Akebono, Shiro Kamo Syousin Suminagashi, Mizuno Hontanren wide bevel, Yoshikane SLD Tsuchime, Tansu Honyaki and Hiromoto Honyaki).
In tall hard foods (e.g.: sweet potato), the passaround knife performs similarly to the other Tansu and the Hiromoto, and maybe the Yoshikane. All of the other knives used to compare felt (and were) thinner behind the edge. Mert suggested using the heel for this sort of produce and this was really useful. The knife goes through the tall hard stuff much easier at the heel. Mert said that this is a combination of the mechanical advantage of using the heel and grind feature in the heel. Having now tried it on several other knives, this seems to work but to a lesser extent, so I guess the grind feature helps. The Tansu honyaki also seems to have improved heel function, but for a shorter length of heel, so maybe this is something that Mert does in other knives too.
The combination of the clever heel and the high tip mean that it's possible to use the knife in a sort of stationary rock chop (like a paper guillotine) using the heel for hard food.
As expected, in shorter hard foods I found that the knife struggled with push cutting but push slicing (and to a lesser extent draw slicing) worked really well.
Food release is better than any knife I have used and the knife performs very well in soft and watery foods like eggplant, zucchini and potato. The Tansu honyaki and Yoshikane come close but even my Mizuno (which I dubbed "zucchini slayer" because of it's good food release) paled in comparison.
It does feel like a monosteel. To me, it almost feels "louder" in it's tactile feedback in food and on the board than a san mai knife.
Onion was interesting. I found horizontal cuts with the mid blade a bit difficult but the tip and even the heel were much easier. Vertical cuts were super easy with the thin tip. the final dice was also very easy.
This knife excels in getting through a lot of produce fast. I shredded whole cabbages and celeries in just a couple of minutes- much faster than usual for me. I think this is allowed by a combination of the height, length and heft of the knife along with the excellent food release.
Reactivity was mild. A mild light grey or off white patina formed over the mid blade (I think after onion).
Edge retention was obviously not an issue in a week and a bit of home use.
I found this knife really interesting. Different areas of the knife are required for different tasks, more so than most knives. But once you learn how to use it properly, it plows through produce very quickly. I thought that it required more careful technique selection (e.g.: push cut vs slice vs rock chop, etc) than I was used to but less finesse when using the technique.
What's are its strengths? I liked the thought that's obviously gone into the design of the knife. It's great at going through a lot of food quickly and has great food release. It's quite versatile. Once you learn how to use it properly, it can be used for most tasks by varying your technique and varying the part of the blade used. It's not very reactive.
What are its weaknesses? It's not a crazy thin behind the edge push cutter.
Who should buy one (assuming you could get get Mert to make you one) ? It's obvious role for me is in a professional environment where it's speed in processing food and its versatility are useful. Anyone who likes great food release will also appreciate this knife.
Who shouldn't buy one? People who want a laser.
I learned a lot from this knife and it made me look at knives, profiles and grinds from a different perspective. And made me realise how much I still have to learn. thanks again for the opportunity, Mert.