I messed around with a Thuringian as well... worked pretty darn well also, similar results.
I haven't tried a coticule yet, since I figured the spheroid particles wouldn't be as prone to fracture as the six sided particulate in the J-nats and Thuringian hones, and thus not cut as "finely".
Maybe that's over thinking it, but isn't that what this fine forum is all about?:)