I don't understand how you got such a narrow DOF. It kind of looks artificial. Maybe if it had been a bit wider and gradual, the textures of the wood and the nail(which looks to be great) would've stood out more.
Neg. space is good. The focus on this shot is really odd and unfortunately, not in an interesting way (IMO). Maybe a bit deeper DOF. I do like the b&W.
wow, this seems to me like it would've fit better in the macro challenge,
just my opinion. a brilliant photo though... cool vignetting and great black and white conversion!