This is my first review here, and part of my effort to actually provide more reviews of products I like an enjoy.
Bestiary 5 is the latest big hardcover Bestiary from Paizo, and if you have seen prior volumes you have a pretty good idea what to expect from this book. This bestiary has over 300 setting neutral monsters for the Pathfinder game, a mix of reprints from past Paizo softcovers (Campaign Setting, Module, and Adventure Path lines for the most part), a few SRD critters left unconverted from 3.5 (Caller in Darkness, Brain Moles, etc) and a large number of brand new creatures. These new creatures are spread evenly across CR ratings, creature type, and role. They include the staples we see in every bestiary, including another set of 5 new dragons, dinosaurs, familiars, and 0HD races. We get further support for some neglected groups (Aeons, Kami, Azatas, leshies), and some groups get more high CR representatives to flesh out there threat range (especially plants and fey). Most creatures get what I feel is an adequate amount of text, but some groups continue to suffer, especially dragons. We also get some brand new creature types, including robots, and the excellent and stomach turning Sakhils
If Bestiary 3 was the "Asian" Bestiary and Bestiary 4 was the "horror and mythic bestiary", than Bestiary 5 is the occult bestiary, with many monsters making use of the new Occult Adventures rules, or having rules and themes that fit well within such an adventure, even if they do not overtly use the power point system. However there are plenty of other creatures that easily fit into any style game, as well as new mythic monsters.
So what are the cons? well for one I would say the artwork was ever so slightly reduced in quality compared to previous bestiaries, with some pieces like the Gravebound being especially bad.
While I am fine with them reprinting monsters from other books, pulling monsters, especially the robots, from the Inner Sea Bestiary was especially annoying. It's a dedicated bestiary book, and with the exception of the 0HD races doesn't need stuff pulled from it. The robots are especially a poor choice, as Iron Gods and the Numeria book had an assortment of robots that could have been reprinted instead.
Finally, I feel there is a bit of difficulty at times with finding niches for monsters. The scum and deep ones sort of step on each other toes, as do the reptiloids and Serpentfolk, their are a bit too many mummy-esq critters, and the Caligni feel like the direction the developers should have taken from the beginning with Darkfolk. This was bound to happen with 1000+ monsters already out there,sooner or later, but still adds a bit of a repetitive quality to parts of the book.
Probably worth also pointing out, although we get more mythic monsters, we received nothing new above CR 25. We have demon lords and Great Old Ones, and so it would have been nice if some of the other outsider groups got similar treatment.
Overall I would say it's definitely worth the buy; There are bound to be at least a few critters that you will get use of or which inspire new ideas, and this book is especially a great buy if you are planning on running an all out Occult Adventures campaign. If your happy with just running with bestiaries 1 or 2, I don't think there is anything in this book that will probably make you change your mind. I'd probably rank it behind Bestiaries 3 and 4 as far as novelty and awesomeness goes, so check those books out before this one.