One guy's opinion: If you own more than a knife or two made of anything of the "premium" or tool steel variety, I'd invest in a diamond hone of some kind.
If you already have a Sharpmaker, get the diamond sleeves.
(do they sell those outright still? I have a set from my old sharpmaker)
What is "premium"? Well... say anything with a high alloy content (molybdenum, vanadium, tungsten) and Rc58 or higher... doesn't have to be stainless. Examples:
SS:
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ATS-34/154CM
BG-42
D2
S30V
S60V
S90V
Non-stainless:
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Vascowear

))
10V
3V
M2
A2 (although I find this easier to sharpen than any of the above)
The V-crock sticks (of which the Sharpmaker is one brand/type), when outfitted with ceramic rods, are not the best tools for reprofiling in general terms. I simply don't have that kind of patience (read: I think they take far too long and are therefore a waste of time, and therefore frustrating). Ceramic stones tend to fill with fine metal dust and don't keep cutting so well after a while.
V-crocks are fine for touch ups.
Get a flat bench stone, or diamond sleeves for V-crock. Or a jig type sharpener with diamonds (Lansky, DMT, Gatco).