I've never used the Sharpmaker diamond stones, but I can tell you that you won't be satisfied with the regular stones if you have to do any significant stock removal on an edge. The medium stones just aren't aggressive enough to remove large amounts of metal without taking a very large amount of time. A search in the Reviews and Testing forum should turn up a few tests of the diamond stones, but to me they seem overpriced. You can get the same results with a $10 coarse bench stone. You see, the only reason to use a really coarse hone when sharpening is to remove a lot of metal from the edge really quickly. Usually, you only need to resort to this when the edge is new and has too steep of a bevel or if it is heavily damaged. Either way, how you remove the metal from the edge isn't too important as long as you don't overheat the edge and ruin the temper. You can use a coarse stone freehand to make the bevel a little shallower before you use the regular sharpmaker stones to finish up the edge. Or, you can rest the stone on the flats of the sharpmaker stones while they're set up in the base, and draw the knife across the stone while holding the blade perpendicular. I would seriously consider trying this before getting the diamond stones, especially if you have a bench stone already. It might turn out to work great for you, then you don't have to spend the money on the diamond stones. Anyway, that's my advice. Do a search and you can find a lot more information as well. Good luck.
