I also have a La Veinette stone (it actually fell so no I have 4 slurry stones ) and this one is very similar in how it sharpens wich is why I think this is also La Veinette. It does the same great job of sharpening my chisels (I use it @ work, I'm a carpenter).
It looks to me like a "La Nouvelle Veine". Those white speckles and small blue lines in the narrow side of the Coticule slice give it away actually. A "La Veinette" should have withe lines in the narrow side of the Blue slice.
"La Nouvelle Veines" can be quite fast, depending on which part of the layer it was cut. (La Nouvelle Veine can be 7cm wide). This one comes from the boundary of the layer, still attached to the adjacent blue.
This one is 6 cm wide and it's very fast indeed so I guess I'm one of the lucky ones. You know, I don't understand why Coticules aren't more known among carpenters in the Netherlands. I've never come across any other carpenters who have a Coticule. They all use coarse, cheap, synthetic stones typically in the 800-1000 range that aren't nearly as fast as my now broken La Veinette or this one.