Kees,

The Belgian blue wears a little quicker than the coticule. After about 10 or 15 razors, when I go to lap it, it's slightly dished in the middle. Very slightly, but still dished. It actually still works fine, but I figure the dishing will eventually cause a problem, so I might as well lap in several smaller sessions rather than one big one.

I use a cotigura to build a slurry, and I usually refresh the slurry about three times per razor.

The coticule hasn't really shown any signs of dishing. I've lapped it lightly once in the past three months, and it didn't really need even that. I don't use a slurry on the coticule, so that greatly reduces the wear and tear.

That's just what I do right now.

Josh