@gbmcleod, you didn’t answer the OP’s one simple question any better than anyone else. The OP’s question was for the Stein mat with a P10, not a Planar 3.
Regarding dust showing on the Herbie’s mat, I would rather be able to see it and clean it. The dust is there regardless of you being able to see it or not. I clean the Herbie’s mat by simply rinsing it off and patting it dry with a lint free cloth. The stock P10 mat that I have is white and I can’t see the dust even though it’s there. The stock mat isn’t very easy to clean.
In my system and for my preferences, I still prefer the Herbie’s Way Excellent mat on my P10 for SQ, elimination of static cling to records, and for its relatively low cost.