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ktinch,

+1 to Ryans' comments.

I have the Norton flattening stone, and indeed after a few months of use I had to flatten that with 160 grit carbide paper on glass !

I also did not like...

binder,

I use my DMT 325 for all my 'razor' hones (Norton & Naniwa), from 1000 to 12000 'grit', with excellent results ( I only have synthetic water-stones, so can't comment about naturals ).
...

binder,

+1 on avatar1999s' suggestion of the DMT D8C.

I used to use carbide paper on glass, before finally going to the DMT.

The DMT is far easier and cleaner to use !

Have fun !