Thanks to everyone for the well informed replies and all the kind words. ... and thanks for the heads-up on this Doc!
Diamonds (especially the very coarse ones) are superior for changing the shape of a cutting edge from rounded over dull back to V shaped and sharp. Ceramics and Arkansas stones can then refine and polish that edge, but don’t ask a ceramic or Arkansas stone to do much in the way of stock removal.
Even a XXC 60 grit ceramic is not in the same league as a 140 grit diamond when it comes to stock removal. (think out of the pack Zwickies, older Grizzlies, and very dull knives). Diamond is just a far more aggressive cutting material.
That said, the 140 grit diamond hone will also produce a true hair shaving edge. It’ll be coarse and toothy, similar in feel and appearance to a file sharpened edge but it will plow the hair right off your arm. This is the most critical step in sharpening anything... getting the blade very, very sharp right at the start, using only the coarsest stone you have. ...and when in doubt, go coarser. There are lots of ways to get from sharp to broken glass sharp BUT going from dead dull to sharp requires the coarsest, most aggressive stone, file, or sometimes even belt grinder you have.
Once the blade shaves, it’s now very easy to refine the edge with finer grit stones to any level of sharpness you may be looking for because each successive grit stone only needs to remove the scratches left by the previous grit. At this point you can refine the edge using either finer grit diamond hones or ceramic/Arkansas stones. Both work very well and we're really getting into the area of personal preference now.
One more “but” though... Diamonds are great for taking a blade from dead blunt to hair plowing sharp in no time BUT... there’s a limit on how fine of an edge you can create using only diamond hones. Used with a very light touch, an XF-1500 grit diamond hone will produce an incredibly sharp edge... way sharper than an out of the pack utility knife blade but not nearly as refined as a 1000 grit ceramic or Arkansas can and not “polished” in any real sense of the word. This is where ceramics, black and translucent Arkansas and stropping are far more efficient than diamonds.
So, it’s really not a question of which type is “better”, it’s more a question of what do you want the stone to do.
Questions?
Thanks!
Ron