As a GM, this has been an invaluable resource to simultaneously: 1) Plug holes in the campaign when I'm too fatigued to be extra creative myself 2) Insert bits of someone who is not myself or my players in the campaign to make it feel more rich 3) Just generally look for inspiration 4) To feel a little bit less alone in the wide open story-telling, game-running skyscape

As a resource for GMs, this book is both detailed enough to provide all of the above, and open-ended enough to provide material for a wide variety of settings and systems. The original source material (Sky Crawl) is incredibly enjoyable, and this just makes it much easier to run with less mental overhead or prep (or frees you up to focus on whatever else in your campaign you want to focus on).

Would happily buy Another Ten Ports in an Infinite Sky and Yet More Ports in an Infinite Sky. =)