Actually I don't have anything at all against violence in movies, but the thought of surreal fantasy elements and brutality sometimes doesn't resonate too well with me at the moment. Maybe it has something to do that i suffer from insomnia for about two weeks now, and I don't want any bad dreams, when I'm able to catch just a little rest. 
No really, don't know what it is exactly, but the thought makes me cringe.
I'll buy "Devil's Backbone" on DVD for 5 Euros though, and if I like it, I'll check out "Pan's Labyrinth".