The maps themselves are very detailed, but end up being hard to read, mostly because every page is covered in some weird LSD dayglo colored layout. I sort of wish they would just had a black and white book at this point instead of bright purple, blue and green colorings over everything. It not only makes the text hard to read, but gives you a headache when looking at it too long. You could almost lick the book it is so colorful. This might be good for something like an art book, but this is meant to be a reference book, so the coloring doesn't work well for this format.
Also, a numbering system for mob/npc placement would go a long way to making this a better product for future books. I'd like to look at the map on one page filled with a list of numbers, and on the opposite page have the numbers and their descriptions laid out.
Overall, still a decent book, just very hard to use.