I've used it a lot actually. Its a quirky stone. I like it best using lather, but the mix has to be right.Have you had any chance to play around with that b hone sized slab since your initial tests?
Edge wise, it reminds me a lot of my Frictionite. Maybe capable of a notch or so better on the sharp side of things. If I lower the viscosity of the medium, I can dumb down the edge to a smoother place.