Recently I bought a few seven dollar diamond plates. The finest grit I got was 1000 and highly abrasive compared the fine diamond rod I was using on the pm2's CPM S30V steel. I think to go to arm hair cutting sharp I'm looking at a few stones including Arkansas and Spyderco finishing stones.
Today a friend of mine brought a nice Arkansas stone to the park and let me take a few swipes with my pm2. I noticed it had a very smooth smooth ceramic finish. I went home and stropped with leather scraps. It's thin paper strip cutting sharp. I can and will do better. It's fun making almost anything work, just as long as the sharpening medium is harder than the blade steel. I have an M390 and a M4 pm2 waiting. Someday.