Storyline: 4/5 
 Characters: 3/5 
 Writing Style: 3/5 
 World: 4/5 
 Iain M. Banks Culture time! And all that it implies: disorienting perspectives, hyperbolic villains, wondrous environments, awesome technologies, new alien encounters, loads of violence, subtle socio-political statements, and non-too-subtle socio-political statements. A genuine feast. 
 What he did again that I really liked: More Culture. Readers of the series up to this ninth volume are well aware of what Contact means and especially Special Circumstances. Banks builds up the Culture even more with Quietus, Numina, and Restoria. Readers will feel like a glutton indulging on the expanded knowledge of Culture intrapolitics and missions. The universe is stunningly expansive and full of spectacles and mysteries. Each new volume is a treat of worldbuilding, and Banks excels at attaching the new pieces to the old. 
 What he did again that I really disliked: Gruesomeness. I've always disliked it when Banks turns the villains into absolute fiends, wholly irredeemable. I've also long been bothered by the sexual grotesqueries. Surface details ratchets these up to an entirely new level (view spoiler)[They took turns raping her while they discussed what to do to really make her suffer. In Hell, the seed of demons burned like acid and generally brought with it parasites, worms, gangrene and tumours, as well as the possibility of the conception of something that would eat its way out when the time came to be born. That conception could equally well take place in a male; a womb was not required and the demons were not fussy. She found the pain astounding, the humiliation and degradation absolute. That particular section would go on for pages as Banks sought new ways to convey horror. (hide spoiler)] In fairness, the gruesomeness has always served a purpose for Banks and the Culture. There is a point. These types of systems (typically traditional and/or capitalistic) generate these kind of characters, and they do these kind of things (so I read Banks as saying). To downplay or ignore it, then, would be irresponsible and would distract from his point. Still, there is a real talent in knowing when less is more, and that is a talent that Banks never applies to this aspect of his writing. 
 Continuing larger themes and points: Utopia. I hear (or read) about these books described as far future utopias, but I think such a statement must be accompanied with a lot of fine print. I've not read any Banks interviews or listened to any speeches, so I can't say what he believes, but the books certainly show an appreciation for some of the trade-offs that would be involved with such a "utopia." There were some strikingly direct scenarios and statements in this one that the purported egalitarianism of the utopia has its own system of winners and losers (view spoiler)[Y'breq, specifically makes this point multiple times when she witnesses the deference and consideration given to Veppers (hide spoiler)]. Thus it may be a money-less society but it isn't necessarily a currency-less one. Also, the role of humans in the utopia becomes all the more clear. This had been indicated in the fifth book - Excession - but, again, our place among the AIs is evinced (view spoiler)[ "Anything I can do?" He smiled. "My dear girl, in Culture history alone it has been about nine thousand years since a human, marvellous though they are in so many other ways, could do anything useful in a serious, big-guns space battle other than admire the pretty explosions ... or in some cases contribute to them." "Contribute?" "Chemicals; colours. You know." Okay, that one was of limited scope and admittedly snarky, but this is yet another Culture novel where we follow a human protagonist and agent - this time Yime Nsoyki - all the way through the book only to find that they didn't matter an iota (well, okay, perhaps only an iota) to the outcome. (hide spoiler)]. I read a lot of ambivalence in the degree of utopianism in the Culture, and the additions in this volume continue with Banks's abashed adulation of this post-scarcity, obtrusive, peace-loving, militarily interventionist civilization. 
 There are lots of other aspects that contribute to this book's tally. On the negative there were a few cheap twists (view spoiler)[the Orbital attack, Jasken's affair, and Zakalwe's identity (hide spoiler)], and the worldbuilding was more halting than is typical for Culture books. On the positive side there is the plot, which was more coherent and resolved than is typical. The biggest bonus, however is what this contributes to the series. It is one of those rare series where the whole is greater than the sum of its parts. The books - each quite good though with glaring flaws - somehow make a truly awesome and masterful science fiction series. 
 My ranking of my favorite Culture novels thus far, best to worst. 
 Player of Games 
 Excession 
 Look to Windward 
 Matter 
 Surface Details 
 Use of Weapons 
 Inversions 
 State of the Art 
 Consider Phlebas