The Astral Adventurer's Guide includes a chapter about the Rock of Bral, which consists of 7 pages detailing that asteroid city. This book, which is available in PDF format from the DM's Guild, uses 96 pages for the same purpose. Obviously, that is a lot more detail. But how has this book aged? Here are my thoughts.
Early on we're introduced to a Bral proverb: “Check your vendettas at the docks.” I like that this philosophy makes the asteroid city into a neutral hub for activity.
This book does a good job of introducing numerous factions, including more detail about the four Underbarons; information about the royal court; numerous trading companies and merchant houses; and Guilds, Societies and Orders. The DM is free to add more, but there's already a lot of detail with which to work.
Details about the government provide the PCs with an opportunity to become involved, if that interests the players. Those who command five or more ships are invited to join the Council of Captains, proving an in.
There are numbers on the map that are intentionally left without description, so that the DM can add one's own locations. In fact, there are 155 numbered locations on this map, as compared to the 30 that are mentioned in the Astral Adventurer's Guide.
All in all, this book seems like a worthy addition to a DM's resources for Spelljammer campaigns. There is game mechanics information that is out of date, but it provides a starting point from which to devise new character stats (character race, class and level, for example). The asteroid city is not affected by changes to the Spelljammer setting, meaning that most of the details in the book remain accurate.
