I just bought a very small coticule to try out, and I am very impressed.
I have had a problem with honing for a while as I cannot tolerate an edge straight from the 8k norton. Up until now I have been using diamond paste to get my razors sharp enough with varying success.
I think the pastes seem to create a false sharpness though - please correct me on this if you disagree. I can make a quite dull razor superficially sharp using pastes, but I think that it rounds over the edge slightly - I have no proof of this but it just seems this way when I consider how my razors were acting.(My other decision was to stop using sandpaper to do the heavier work and to buy a 1k stone)
Anyway, to get to the point the coticule seems to put a very fine edge on whilst keeping a very flat bevel and also gave me the most comfortable shave I have had for a long time. Now I just have to get it right on all my razors.
I'm very tempted to get a higher grit stone to see if it improves even more but I can't afford the 30k shapton yet!
Thanks for all the great advice that led me to buy this eventually after nearly a year of shaving!