Well, I gave up and went back to the 8k for the Boker - as before, I hit a plateau and wasn't able to get the edge any sharper on the coticule, whether with plain water or a slurry. Differences in pressure didn't seem to make a difference, either - ultra light or a bit of pressure, it just wasn't getting any sharper.

Question for the people with both - could you describe the difference (if any) in your stroke using the 8k vs. the coticule? More pressure or less?

I've still got the other Wapi to finish - I may do just enough on the 4k to smooth out the scratch from the DMT 1200 and then try again with the coticule.

*sigh* It's damned frustrating, though - I was hoping to spend $175 and get something that would (for the most part) replace the 4k/8k...and I just can't get it to work.