
Since the contrast paints are so translucent you really do have to practice good brush control, yeah, unless you're using that translucency for blending and such (which I'm doing more and more as I get used to the paints). I've said it before, but the GW ad copy of "slap on one thick coat" really does the line a disservice.
(That said, I really have no idea how I'm going to use contrasts to do the gribbly weathered armor on the nurgle warband, but by gum I'm going to try.)