The book is well written with great layout and graphics that set the tone and immerse the reader in the portrayed future, while remaining easy and entertaining to read.
The book systematically covers the inner system, starting with the solar corona and out to Mars, as well as an assortment of inner system asteroids and martian trojans. The book expands and adds to the information in the Eclipse Phase book, but most of the material in this book is probably understandable without having read the core book. The descriptions of people, environments, habitats, orbital stations, politics, transportation, and so on are evocative and plausible. They are also done from the viewpoints of various local Firewall agents with different backgrounds and political views. This not only makes the reading more interesting, but gives more insight into life in the future of the solar system and reminds the reader that what they are reading is an opinion and not necessarily the whole story or even entirely accurate. There is lots here to get players thinking about, frm how to play a conservative and prejudiced “Loonie” to a Barsoomian redneck from Mars. For the GM there are lots of political agendas, habitats and dangling plot hooks and descriptions that conjure up ideas for cool scenes everywhere. Perhaps something involving piracy of airships travelling between the floating Aerostats in the upper atmosphere of Venus, or something to do with the remote controlled Quartz morphs working the high temperature and pressure mines of the Venusian surface going missing?
The Planetary Consortium (one of the most powerful power blocs in the setting) is described in detail with information and ideas that go a long way to help illustrate the various parts and agendas that make up the consortium and in the process creates a lot of useful plot hooks.
Game information is all covered in the last part of the book. This is great both because it means that the rest of the book is completely rules agnostic, which is very handy for a setting book you can use with your own favourite system, and because it means that all the stats and rules for hazards, morphs, gear and so on are collected at the end. Even if you don't plan on using the Eclipse Phase rules this section of the book is still useful, not least for the secrets and plot hooks.
I bought the PDF thinking that a Sci-Fi transhumanist themed setting like this would be best read on my tablet, but although the core Eclipse Phase book has been adapted for e-readers Sunward has not and it takes a long time to turn pages on my Nexus 7 and the page format is a too big and would probably fit something like the Nexus 10 better. On a computer, and potentially a more powerful tablet, the PDF is first class and is a joy to read. I'm not rating it down because there was no claim about this product being tablet friendly. In the end like the other Eclipse Phase books, Sunwards is just so beautiful that I had to also buy the hardback to hold it in my hands and read it on the sofa (and other unspeakable places). Very happy with that decision.