Subject line pretty much says it.
Curiosity. What else would you expect the motivation to be?Just curious as to the motivation for the question?
I think @eKretz has done the DMT 320 stone one and done followed by 2 strops. I assume it's the same person from the scienceofsharp comments.
Keep in mind of course, a grit is not a grit, and a well worn DMT 320 is a very unique beast.