Mostly positives here.
It was an audiobook, narrated by the excellent Peter Kenny, which is a good start point. Versatile range of accents, making the characters instantly recognisable, because he's just so consistent.
A nicely convoluted plot around a sprawling wealthy family, the clan Wopuld, complete with black sheep, set against the background of a bid by a US games corporation to buy out the family firm. A powerful (but aging) matriarch, devious and unscrupulous. Skulduggery. Some well-concealed plot twists. Teenage lust à la Adrian Mole turning to middle-aged angst in the mostly-sympathetic protagonist, Alban McGill. Some lovely comedy from aunts Beryl and Doris.
Some negatives, though.
Many of the characters are stereotypes - Fielding, for example, and Cousin Sophie (the object of Alban's teenage lust). They lack depth, though you might defend this on the grounds that the tale is told from Alban's point of view, and the narrative reflects that Alban never really tried to understand his relatives. Even Sophie, whom he never sees as more than the object of his sexual desires.
The story takes a while to get going. The first chapter almost lost me - we meet Fielding first of all and there's no empathy - he's just a wealthy businessman, thrust into a Scottish slum, petrified that his car will be stolen (or keyed).
But then the first plot twist - he's agin the takeover. Suddenly I like him, and my interest in the book picks up. It drags again though in the following chapters. We get a guided tour of Alban's teenage years, his first meetings with Cousin Sophie, and it becomes very meandering and (as I said) Adrian Molesque. In hindsight, a lot of what happens here feeds into later twists, but at the time it just feels like Iain Banks is indulging in teenage male fantasy.
The final negative is Alban's atheistic rants and introspective musings, which just went on and on at times. It's a facet of many of Banks' writing, normally kept somewhat under control, but here it got downright fiery-preachy, sentences piled one upon another, as Banks restates his beliefs just in case you didn't get it the first time.
The novel gets going again as the moment draws closer when the decision on the sale will have to be made. Interleaved, we learn that there's a mystery that surrounds Alban's birth, and the suicide of his mother. Black sheep, secrets and skulduggery...
The threads all come together reasonable neatly, if a little predictably. There's a nice little coda, too, showing Alban apparently at peace with himself.
In hindsight, it feels like another Espedair Street. That's OK, too.