This is my first read of a Greg Egan book. It is written in the first-person, present tense - which might be important to some readers. It is the first part of a loose trilogy, written in the early 1990's. I don't know the author's background but I'm fairly sure he has some qualification in the sciences.
The first third of the novel sets up a mystery surrounding a missing person and introduces the main character. It is an extremely well-written segment with that first-person, present tense style adding to the tension. The main character is developed slowly and thoroughly, though ancillary characters are less well described. The near future world of the setting is very imaginatively built; the technology of the time is inventive and believable.
The second two-thirds of the novel is very heavy on the science of quantum theory, with the story line suffering at its expense. I can't say that I always followed every aspect of the physics but the concepts under discussion kept me interested, even if they were overly drawn out. Unfortunately, the story didn't quite come together by the end, with the explanation of the science theory overwhelming the fictional "mystery".
Certainly, I enjoyed reading this book and found Mr Egan's ideas intriguing. Its a pity, though, that the underlying mystery story didn't maintain its prominence to the last page. I'll read the next in the series at some stage.