That's a cool stone. For some reason I thought it was from the ol Preu mine but I could be wrong. Seems like I've seen it before on coticule.be.
I stay on my cotis on water longer than most have recommended above. I don't count strokes but I'd guess somewhere between 75-100 on a 6x2.
As for hybrid vs yellow, my edges are notably keener off the hybrid side, especially when I take the time to make a hybrid on hybrid slurry. But as always, YMMV