[phaedrus]

I think some DMT plates wear quickly- there seems to be a lot of variability, if you can believe half of what you read on the interweb.  I have a DMT C that's been used frequently for flattening & sharpening for at least three years and it's still going strong.  That may be the exception or the rule, I don't know.  They're sure nice while the last, though!

 

[phaedrus]

I sometimes feel that I have fallen for the 'forever' of the DeBiers et al. of Diamonds, they seem to be rather expensive for what you get, less of a bang for your waterstone buck, if you will. In this regard, it sounds much more reasonable to use your drywall screen and large flat surface.

If you're just a regular guy sharpening his own knives at home and flattening your stones as needed, I truly think a DMT XXC might last you the rest of your life. Unless you get a bad one; that does happen. But a truly bad one usually fails ASAP and will be replaced under warranty. Man, I just wouldn't want to dink around with the drywall screen (even though I have a granite reference plate) when the DMT is so dead simple, fast and easy to use.

 

[phaedrus]

Yeah, there're lots of ways to flatten.  I'm drawn to the neatness and simplicity of the DMTs; I can have stone in one hand and DMT in the other and just flatten under some running water most of the time.  When used just for flattening a DMT will last a long time.  You may be right about them for actual sharpening.  I've had good luck but we'll see in another year or two if they're still going strong since my current practice is to skip my coarse stones much of the time and use the DMT XC & C instead.