I bought a copy of this after seeing several recommendations on Mumsnet. I just finished it and feel compelled to start a thread as I thought it was hugely disappointing.
All the characters were vile, the treatment of South African politics was extremely superficial and I guessed half way through that Laura murdered Gay. I also found it bizarre that while Laura could justify killing Gay to herself, there was no reflection on her part about the fact that an innocent man was subjected to the death penalty because of her.
I think it would have been a better book if it had been fleshed out a bit more.