Currently I do mine on an EP with what is described as a super fine diamond stone it takes around 50 plus passes to get a good edge and then diamond tape 3000 grit to finish . I have tried courser diamond plates the Atoma just micro ship even the 1200 as the diamonds are grouped .
I would love some diamond plates for the WE say 1200 & 3000 the big advantage it has over the EP is the time should be virtually halved as each side is done at once the diamond plates need to be very smooth unlike the Atomas for ceramic knives.
I had 5 ceramic knives to do off one boat the other day a lot of female chefs like them for their lightness and they are good for cutting fruit.
Like it or not I think ceramic knives are here to stay they are slow to sharpen if they have a lot of micro chips it can take 100 passes over the blade to fix them which is why I charge double to do them (in view of the time it still is not enough & fortunately it is a first having 5 to do out of a job of 22 knives) but it would be good to have a stone that eats ceramic blades for breakfast.