Raft is Stephen Baxter's first book, and the first of his that I encountered. I also think it's his best book. While Baxter normally focuses on solid science, this book does a considerable amount of hand-waving to make it all work. The galactic cluster seems to be full of breathable air, for one thing. Still, it's credible enough to work, and the ramifications of the strong gravitational force are interesting. For one thing, it's a very different milieu than most SF stories then or since.
Where Baxter's books normally fall down is on character. He seems so focused on credible science that he has no energy left over for characters. His books are technically interesting, but emotionally dry. His natural stance seems to be as a distant, dispassionate, almost clinical observer. Raft is an exception. It's not exactly brimming with personal drama, but its protagonist, the Belter Rees, is a genuine human with genuine relationships. He wants things, feels things, cares about people, etc. I wish Baxter hadn't left this human element behind when he focused more on science.
Raft isn't perfect. Both the science and the personalities are a little too thin. But it was definitely an eye-catching book, and one that induced me to buy many, many more Baxter books, until I finally accepted that the balance in this one had been something of a fluke, and that Baxter was really more at home with thought experiment fiction.
If you haven't read Baxter, this is the best place to start. If you have, but don't know Raft, you'll enjoy this. If what you want from science fiction is deep characters in an FTL ship, this isn't the book for you, and really nothing by Baxter is.