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I don't have a Nainiwa or a Shapton glass stones but both have a reputation for speed. The Shapton's are likely the faster of those two.

I recommend that you try 5 passes then shave test, repeat...

That depends on what 12k range hone you would use. A phig would need a lot more passes than one of the nicer synthetic hones. A fast 12k would need as little as 5 while a phig may need 100.
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