The Hasegawa and Asahi cutting boards will have cutting surfaces superior to any other I have used. Both for protecting the knives and actually cutting food more effectively.
Bamboo is hard on cutting edges; it's penalty work for my woodworking neighbor. Various synthetic boards chip on me; they aren't expecting my sharp knives. And a company that flogs pure titanium pans on Facebook also sells titanium cutting boards, which tipped me off that they have no idea what they're doing. Sure, titanium is softer than steel, but that's far from the whole picture. I'm loving my Hestan Titanium Chef's Pan which is actually a molecular titanium surface deposited on steel that is 4x stronger than steel, and slick, leaning in the "ceramic nonstick" direction but more durable. But pure titanium is a terrible idea for a pan. Luckily, my knowledge of cutting boards saved me from a mistake.
The Japanese, of course, are expecting sharp knives.
I have long had a raw butcher block work surface in each kitchen, with an overhang to mount tools. I wash the surface by scraping with a bench knife into an (empty) steam table insert that also collects compost as I work. Since getting Japanese cutting boards, I only use the bare wood some of the time, like for prepping winter squash.
I am delinquent in bleaching my Japanese boards again, which does work. I lay down paper towels on the board surface in a utility sink, pour over a bleach mixture just strong enough to turn the paper towels back to pulp. But I'm not expecting Michelin inspectors any time soon (their loss!) and the stains don't bother me. Still, black? Clever.
600cm, wow. Cutting the Hasagawa boards (which you don't plan to do) would expose the wood core. Artists know this one: Cut both ends, make it look deliberate. 😀