I loved the concept art, especially the outdoor scenes, but I found the writing somewhat frustrating. There are multiple pieces of information and verbatim text that get repeated twice or a few times, both between the introduction and the main text and within the main text, more so than I think I normally see in such books. And there are several errors (none of the monsters can be called "cannibalistic" for eating humans as they are not human themselves, and gingerbread men, monstrous or not, cannot be "crisp dough" because...that's not dough anymore.) I felt like it needed just a bit more editing to bring the text up to the level of the images.
Also, I do not like it when art-of books refuse to discuss the film's ending. The idea that anyone reads these BEFORE the film with the expectation that they won't be spoiled is a tad silly. (And the book does spoil everything else...)
Still, it's a worthy book for any fan of the movie or of Krampus. It isn't as elaborate as other releases from Insight Editions--it hasn't got any inserted bits of paper or foldouts--but that also means you don't need to deal with any obscured text.