It's way too overrated. If I was to rate it, I would give it a 7/10. People say stuff likes its the first anime to do this, etc (Which it is not) and it just kinda' annoys me that the anime mostly runs on an okay story and shock factor. I went into it expecting a dark fantasy tale about Magical Girls, and all I got out of it was a Magical Girl anime with a few shocks here and there.
12 episode was also way too short, I was hoping for a lot more action but oh well =(
The best thing about it is the art, other then that its an average mahou shoujo.