I've been reading Alastair Reynolds' books for many years now, I don't exactly how many, I just know it's a bunch. I started with Revelation Space, continued through the books of the Revelation Space universe and I've since progressed onto his other works, Pushing Ice, Century Rain etc. and now House of Suns. The RS universe remains my favorite, and I hope he isn't done with it. I've decided to catch up my reading with Reynolds' work, putting other books on hold until I do. Next in line is 'Blue Remembered Earth'.
Now enough about that. I have mixed feelings about House of Suns. On the one hand, I felt it was good enough, it certainly wasn't terrible, its idea's were creative, but at the same time many of the characters felt very two dimensional.
The plot is one of the farthest flung things I've ever read in sci-fi (outside of Isaac Asimov's absolutely brilliant short story classic 'The Last Question' which extends to the end of the universe itself; you can read it here, don't deprive yourself if you've never read it http://www.thrivenotes.com/the-last-question/).
The book follows two main protagonists, Campion and Purslane six million years in the future, and also a third Abigail in a much less distant future. Humanity and its descendants are a vast sprawling conglomerate of constantly rising and falling civilizations. At the beginning, prior to galactic expansion, Abigail Gentian, one of the book's protagonists 'shattered' herself into a thousand clones and sent them out to explore the galaxy and record their observations. The clones are functionally immortal, living from their creation to the far flung future which most of the book is set in, but spending much of that in stasis as they travel among the stars. The book carefully explains that she wasn't the only one to do so, others did so as well, and the resulting meta-civilization was known as the Commonality of Lines.
Every 200,000 years members of the line meet up to swap stories, experiences, observations, etc. But someone attacks the latest reunion of the Gentian line, annihilating most of those present and the mystery of who and why encompasses most of the book.
What to say else to say about it? Kinda flat, I guess. The book feels like a murder mystery at times, at other times it's a space opera. The promised romance between Campion and Purslane (no spoilers here all of this is straight from the backcover), was fairly non-existent. The book makes it clear that they travel together, there's a reference to pre-stasis lovemaking here, an I love you there, some implications of romance, but all we're really told is that they're a couple engaged in a forbidden romance. There's abit more evidence of it at the end, but all in all the romance subplot is pretty nil; I don't think Reynolds likes writing romance into his novels or is any good at it. I'm not sure which, I don't recall him ever touching the topic in any of his other novels. I never got a terribly good feel for either of the two main protagonists, either. Campion is a bit of a loose cannon, I guess, Purslane abit more cautious. Didn't particularly care about either one.
Other characters get better treatment in development. Betony, for example, is developed as a kind of villain, but is given enough depth to be something else as well. There are other quibbles as well. The House of Suns dominates most of the book, near the end the plot shifts off course, onto something different and totally forgets about the titular house altogether. I find this irritating. If your going to make it the title make it the focus for the whole book, not two-thirds when you can drop it and work some other angle.
The book is divided into six parts (why I'm not really sure), and each part prefaces the main story with a chapter about Abigail, the founder of the protagonists' line. In the Abigail storyline, she spends most of it as a child, playing with a large toy called Palatial which simulates a fantasy world for her. Her play is accompanied by a little boy, who is never named, from another part of the solar system. Eventually Palatial is revealed is to have a bleeding effect on it's players, causing them to believe the simulation is real. By the final Abigail chapter all of this, Palatial and whatnot, is finally dropped and stuff that is actually related to the main storyline actually gets involved.
All in all, the entire storyline involving Palatial was almost completely pointless, besides implying one big, though unnecessary, truth. I was a bit irritating that 5 chapters of reading that storyline and then the entire thing was dropped like a bad habit. I think Reynolds intended it to parallel the way the main story played out, but why? The whole thing was pointless.
To sum it up, if your Alastair Reynolds fan, read it, add it to your bookshelf, then forget about it. If not feel free to skip it.