"Light" by M. John Harrison (Gollanz, 2002)

If you like low-life Neuromancer style, this might be for you. There's SF - "Her sensorium, analogued to represent fourteen dimensions, echoed with relicas of itself like a cathedral built in 'brane-space" and a spaceship called "Remove All Packaging" - but also much that might be in a well-written mainstream book - p.168 for example. The guy can certainly write (shortlisted for Guardian Fiction Prize, etc). Maybe I prefer his short stories though.