First things first, this is unsurprisingly a book a monsters with a heavy emphasis on beasts. It is not attempting to be complete but instead to give you many interesting and detailed options. There is tons of gorgeous art in this book and a great many iconic monsters and demons.
Some will complain that they cannot find a certain monster in the book but between what is covered in this (and the common monsters from the Almanac) you have more than enough to throw at your players.
I really enjoyed this PDF and am looking forward to have the printed book in my hands.