I have the 240mm Kohetsu and I highly recommend that knife.
I also have the 240mm Anryu Hammered and I really love that knife, though it is in Aogami #2 (http://www.chefknivestogo.com/kaanasgy21.html
). A bit more of a workhorse than the Kohetsu, it is loaded with character.
BTW, monosteel carbon knives are fairly uncommon. Most are either perennially out of stock because they are in demand, very high priced, or both.