They don't specify. It's almost certainly VG-1 hardened to 58-59 RCH for whatever that's worth. Really nice knife.
240 is more productive and just as easy to control as a 210, once you learn how to hold it. Also, Japanese made knives are signifinicantly lighter and more agile and easier to control than German made. If you're used to an 8" German, you won't have any trouble at all with a 24cm Japanese.
But, at the end of the day, length is a matter of taste.
The real issue with most people is sharpening. Japanese knives are relatively thin and are made to favor sharpness over power. If they aren't kept very sharp they get depressed and sulky.
BDL
Edited by boar_d_laze - 2/1/12 at 7:45am