The Temporal Void is not as strong as its predecessor, The Dreaming Void, but it's still a strong book. The book continues the story, but this time the SF side is stronger than the fantasy. Both have weaknesses. On the SF side, key character Araminta experiments with different romantic/sexual relations. Unfortunately, it comes across less as exploration of future social models than as an exercise in wish fulfillment. It's distracting, but not really intrusive. The other complexities of the SF world work better than in the first book - partly because of greater familiarity, partly because they focus more on individual relationships.
On the fantasy side, the story remains interesting, if a bit political. However, it weakens substantially at the end.
Overall, a worthy successor to The Dreaming Void, though I wish Hamilton had paid more attention to the ending and wrap-up.