Honestly - it went on my "favorite" list. I also think that the artwork is amazing. Unique compared to other mangas. Is it disturbing and full of gore? Yes, but that's what makes it so different and somewhat exciting. If you're sensitive to these kinds of things - I do not recommend it for you. But if you're a fan of bloody scenes and horror... fascinated by psychopath's mind - it might be perfect for you.
Like some other folks mentioned - don't get put off by the rating. Most of these are because of people not being able to handle such messed up manga. But it has a great storyline, well thought through.
Feeding lamb