Let me start by saying the Creature is my favorite of the classic Universal monsters :)
The premise of the book sounded interesting...time-travelling back to the prehistoric period to learn about the Gill Man in his natural habitat. But once you meet the monsters, so to speak, it removes the mystery of the Creature seen in the films.
The ending very much reminded me of a vintage monster film where there is an epic crisis that is wrapped up very quickly.
It began interestingly enough; however the climax was laughable - and not in the good way. If you like time travel, aliens, zombies and plagues its for you; if you like good ol' monster mayham - then rent the original.