This isn't a bad book in comparison to other D&D tomes on religion. I found some useful stuff in it that I will use in my games.
The problem I have is that I've also been reading Runequest / Glorantha books like the Cult Compendium and the Guide to Glorantha. In comparison you realise how much D&D is missing by not having it's gods deeply intertwined with the history of the setting and the cultures of the land. Also a lot of the gods in Monster Mythology feel like they've been built to a template. In comparison Gloranthan gods feel individualistic. It also misses different interpretations of the same gods by different cultures and also the different way religions work between cultures.
[3 of 5 Stars!]