Perhaps it is due to the small size of the representation here, but I get the impression that you've overdone the SilverEfex - the equivalent of over-saturating a colour image. The blacks seem too black - almost lifeless without detail. The contrasting highlights, would be appropriate if the rock was glistening wet, but the rock (and roof) don't look wet. I understand that you may want a "dark", contrasty, moody image to portray the subject, but just because you can, doesn't mean you should.
However, that being said, an image treatment like this might serve well on, for example a rock or punk music album cover.