Whats with all the hype over Japanese knives?

Good Japanese made knives get sharper and stay sharper longer than Germans.  They're also lighter and more agile with less tendency to wedge.  Not all Japanese knives are good, and that includes some fairly pricey, popular knives with an unfortunate tendency to chip -- like poorly sharpened Shuns; but a great many others are excellent. 

If you believe a properly sharpened Wusthof Classic chef's knife can portion sushi -- let alone stand up to an entire service of precision cutting -- as well as a properly sharpened Tadatsuna White #2 yanagiba, that says more about you, your skills, and your level of discernment than about either knife. 

I could speculate as to why some pastry cooks prefer, clumsy, soft, heavy German knives which never get very sharp, wedge at the least excuse, and need constant steeling, but it would be rude. 

BDL

90% of the time it's just hype and bragging rights.

Where the good Jap knives realy shine is in cutting meat, this is where a really sharp edge shows up.  To get to this stage, you need to unerstand about blade geometery,and sharpening techniques. Again, the large majority of knife owners do not have this knowledge or the aquired skills  A sharp edge is not infinite.

Because of the blade geometry and materials,Japanese knves can take a much more extreme bevel, which allows them a wicked sharp edge,but also a very fragile one.  It is a trade off,but then all steel alloys are a compromise of toughness, brittleness, hardness,edge rentention and the ability to resist acids. 

Where the German style knives shine is in about 75% of the other related work tasks in a commercial kitchen.  Cutting and coring cabbage (What better to cut Rot Kraut then a Henckels?) Chopping herbs,peeling and cutting squashes, boning out meats, and "in my day" hacking up 5 kg slabs of couverture.  

I can also take paper thin slices of smoked salmon with a 30 yr old "Driezack" (older name for Wusthof) smoked salmon knife made especially for this purpose,an the design goes back over a hundred years.  On the other hand I have to admit that many japanese knives are ideal for cutting delicate meats like fish.

I hve amused myself to no end by listeing to "japapense knife conversations".  You would think that the rest of the world had, prior to 1945,  manufctured it's tools, ships, weapons, surgery equipment, barber equipment, etc with pointy willow sticks hardened in the fire pit....