+++Artwork!+++
First I must say that while they offered some impressive artwork in this book (the picture of who I believe is Asmodeus stands out the most), perhaps half of the pictures in this book are maps of the many planes with titles telling you the general locations of each plane. However the bestiary offers an impressive handful of pictures on the Astradaemon, Keketar protean and a Vulpinal. The artwork for the most part stood by the same amazing quality you'd expect from pathfinder's bestiaries. While it was lacking in the quantity department, it more than made up for it in their superb quality.
+++I'm dizzy! There are so many locations!+++
Don't worry! There's a briefer at the start that breaks down the 'inner planes' which include the elemental planes and the 'outer planes' which include elysium, axis, the abyss, the maelstrom and many other extraplanar regions! You can decide from the brief descriptions they give of which locations you'd like to use and which might be better saved for later (the more hellish realms are quite dangerous).
+++But how do I get there?!+++
Fear not! There is a section within the book speaking of the items you may use to get to other planes, aside from portals both natural and crafted. That very section also mentions some of the spells that were created to also traverse the multiverse. My apologies, were you speaking about the routes themselves? Yes, the book also talks about the astral plane, the plane which connects all others. It also speaks about the shadow and ethereal planes in addition to how each intersect and meet at certain points. Each are traversed differently and suffer from different dangers.
+++And the planes themselves?+++
Here is where the book truly shines, offering a TON of any information one could ever want for. Do you wish to know of heaven? You are told of its inhabitants and its society, the many levels of heaven and just who occupies each. You are even told of its most notable sites. With such information, you can decide where you want your players to go in their quests and just which areas are most useful to them. This remains true for hell, abaddon, elysium, the maelstrom and so on. You are told of who lives upon each plane and what features exist there. Do you wish your players to visit the plane of air? Don't know how they'd move around in such a place? The book describes different planar traits and how one would move in such a plane, describing such things as objective and subjective gravity, the difference in the flow of time and even the possibly hazardous environments of many locations. The book tells of the elemental planes as well, informing you for instance of the plane of water and the city of Vialesk, apparently one of the few cities in the plane of water capable of supporting air-breathers.
+++What about the infrastructure? What happens to souls and did the deities create them?+++
This book also talks about the life cycle of the soul, how it is created and what happens to it after death. It speaks of where they are judged and what they may become. It also speaks of the dangers one suffers even after death, of those that harvest souls and even devour them. There is even a section on the history of the planes.
+++Overall?+++
I now know what pathfinder's multiverse looks like and just what my players can hope to experience in their travels. Perhaps I may even allow them to become evil and turn soul traders, stealing the afterlives of those travelling through the currents of souls departing the material realm. A good book to get for your players to start touring the multiverse, perhaps even visiting the beautiful yet deadly city of Dis.
+++Bonus for your consideration!+++
You also get to read more about the wondrous axiomites and are given about two pages on them, including a statted out CR 8 axiomite. You can read about their ecology, habitat and society and the origin of the inevitables. They also include information on the proteans in the same regard.