Same here, got the book through their kickstarter.
I like the monster write-ups which have been definitely inspiring. Their tie-ins to the Midgard Campaign Setting are still usable in any campaign setting, with very little or no tweaking at all. I also like the "lived-in" feeling that the monsters give the game world. Even though I don't use Midgard as my campaign setting, creatures like the suturefly give interesting ideas for encounters.
I like the look of the monsters, the illustrations are very good. I really like the layout of the book, which makes it very attractive.
I'm very glad for the Monsters by Level and the Monsters by Role tables on the back of the book. It makes it very fast, and easy to find a monster for a particular situation.
I can't wait for the physical book to arrive.
I'd definitely recommend getting the book, the price for the PDF is very attractive.