Chasm City takes a bit of a step sideways from Revelation Space, which on more reading makes perfect sense. It’s not a sequel but rather a novel set in the same universe, a bit earlier in the timeline.
From the worldbuilding perspective, this extends and deepens what came earlier in Revelation Space, in particularly giving us a few insights into how early colonies could have been created in a universe without faster than light travel, the origins of the Melding Plague, and more backstory about Chasm City. All around, a very interesting world. It’s a relatively grim possible future, but a well imagined one.