This book has an immense span of imagination. Banks has an ability to create ideas that are just over the boundary of the absurd and yet implements them so that they seem almost homely and reasonable.
There is, in my limited experience of writing, a sort of mental crash-barrier between the familiar and comfortable and the strange and disturbing.
Great SF writers possess a kind of intellectual bravery in vaulting the barrier and hauling the strange into the familiar.
When writing I will pursue an idea as far as I can but there is always a part of me too willing to reject a plot or character or situation as too ridiculous for further exploration.
Feersum Endjinn starts superbly: with typical Banksian whimsy gradually revealing an immense canvas that (had I ever thought it) I would have immediately rejected.
There is a tendency towards dues ex machina in the plot: and the Bad Guys aren't as unpleasant as most Banks villains. However the story is compelling enough and the Good Guys interesting enough to follow through.
An excellent read.