I completely forgot I had a Grecian, busted it out the other day and liked it a lot. Have not found a great use for a standard llyn idwal yet. But I may not have a great example.
Out of three aizu, I only thought one was a top class edge stone.
Believe it or not, cotedupy didn't turn me onto Turkeys,
@demirtasem did. He has a preference for the coarser grey ones, getting closer to a 2k edge and better for pro duty. The darker finer variety is a-ok for a home cook. It may become an intermediate razor stone as well, if I can effectively smooth the surface enough.
A Dalmore blue also leaves a fairly good knife edge. A bit slow but they can also be beautiful. Worth the work.
Diamonds aren't my favorite fur edges. AlOx is my ideal abrasive for steels, diamonds feel like more of a necessary evil for high carbide, or a power sanding option.
But yeah that good Arkansas novaculite is hard to beat. Fast, aggressive, clean.
But for whatever reason my coticules keep multiplying. Even though I get better feeling edges from many other stones for both razors and knives than many cotis, I keep chasing them. Because the good ones can be brilliant.