Opera, this is the kind of setting I mean. Plugging the math node into the texture map in effect turns it into a standard bump map - you don't have to alter the defaults at all. Then just decide how much displacement you need. It works well (IMO) with Koz's maps *because* he uses sharp highlights - you get a nice, contrasty bump map. The result is still a bit "noisy" using the draft settings but it looks great in a high quality render. I've started experimenting with GlowWorm and this technique. I think that if I use quite a high displacement value for the light passes (high enough to look horrible in a normal render) I'll be able to get highlight and shadow in the hair to look great after some postwork. I'm not there yet, but some early attempts are looking promising.