I love Banks, so I'can't (and don't even try to) be objective. I've loved the way it's written: I can easily imagine Banks quietly laughing, while he's written part of this book. Very nice the alternation of second person (quite unusual) and third person in the telling.
As usual with many of his novels (be them SF or "mainstream") you have to read almost till the end to understand the title, and to which (or whose) complicity is he referring to.
The story in itself is fairly simple, but the characters are wonderfully depicted. And even raunchy at times.