One of the things that Chris makes sure of with all our knives (barring a miniscule few custom pieces that he has made)is they they are completely capable of cutting. They may not keep looking beautiful (damasucs, decorated etc.) after working and they may not cut as well for extended periods but each knife can be used for the primary function of a knife - cutting!
The Kathathu is sharpened in exactly the same fashion as any of our fixed blades. The blade geometry is such that the edges are as sharp as any of our knives and, giving the specifics of the design, it would perform exceptionally. I would imagine, however, that few people will actually put the knife to the test!
Anne