I purchased this product simply for the monsters, which I had heard were all very original. I would agree that many of them are, and I definitely found a number of very interesting things which I can either build off of or use in a game of my own. However, I besides the gripes some may have about the art (I don't really care for it, but it isn't extremely important. I get the idea of what the monster is) the problem I found with many of them was the heavy meta-narrative tied to them, as well as many descriptions used relying on modern equivalents. To me, these sorts of things would be very immersion breaking to a group, telling them in a Medieval fantasy game that "the monster sounds like a car engine that just won't turn over no matter how many times you turn the key" and so on.
I also personally didn't care much for the general prose of the writing, but again, that is a personal sort of thing. I would say that these sorts of things can work for the right group, but that I do have such a group.
[3 of 5 Stars!]