I've already spent an awfully (and ashaming) long time on this piece to get this... well...result.
I'm particulary disppatointed by how soft it looks. I'm wondering if there is a flaw in my way of using brushes. Most of the time I use 50% opacity on an hard brush excepted when I blend and use around 10%. Always 100% flow. It's probably only a detail and bad results come from somewhere else. Advices, paintover, talent transfusions would be very welcome ;-)