This was a bit more work to get through, for me, than many of Banks' other works. Sentence-by-sentence, still lots of fun—the more attentively I read Banks, the more wordplay and cleverness jumps out at me—and the big ideas are good. However, the multiplicity of plots and view-points is a little overwhelming; what initially seems like three storylines proliferates and multiplies, with each point-of-view getting only fairly short textual chunks at a time. The result is a kind of attenuated feeling; there's so much not immediately obvious in each storyline (standard for Banks) that I just got a kind of collage of events, with things not really lining up until the last fifth of the book or so, when Veppers' real motivations become clear.
To real it back for a second to synopsis, Surface Detail is a Culture story: broad galactic space opera. The Culture itself is a multi-species civilization run primarily by Minds, highly advanced and typically ship-born AI. As it's basically a post-scarcity, hedonistic, space socialist utopia, tension in the Culture comes from its interactions with other civilizations—lower-tech groups that it sometimes attempts benevolent interference with, equivalent-tech groups that are potential threats, and "Elder" or "Sublimed" species that typically don't participate in galactic life, but may have powers far in excess of the Culture if they decide to do so.
