I like it mostly for the metal references, myself. I mean, okay, it has a decent if horribly cliche plot, but it - together with all the allusions - make for some good chuckles. Mind you, I'm not even a hardcore metal fan - one could find a lot more to thrill/annoy him/her.
Overall? Nice, but nothing to write home about imo. I liked Slayers or Record of Lodoss War (did they stop working on it) a lot more, but I can't find more than the passing chapter on it.