Am looking to upgrade from a random set of henkels and etc that happened to be lying around the house to some sort of japanese style gyuto. I used to be an avid knife collector, and trained in japanese style honing by my grandpa who was a master woodscraftsman. (in japan) So i think in terms of care and sharpening, im pretty ok. I can make almost anything razor sharp. The only issue is that as im looking around for gyutos, im seeing that the sizes come in 210, 240, and 270mm. Im just cooking at home so i dont really need anything that big.. I do see an occasional 180mm or 170mm, which is more what im looking for, but that limits my selection quite a bit. Is there a particular reason gyuto or chef knives are that big? Should i just go with a 210 and just adjust to it? Personally, i have never seen anything a 170mm santoku couldnt handle, so the 210 or above size is hard for me to justify. Next question is about metals. Forgers and craftsmen make knives out of a limited selection of metals. Say if brand a uses metal x, and brand b also uses metal x. If they both made gyutos of the same length, would the only difference be in shape variation and weight distribution? Im seein lots of knives being made with the same material, so its hard to see what the difference is. (apart from the affect of blade design). All inputs appreciated!