I didn't find this book "genuinely original and profoundly imaginative" as touted on the back cover. I've read other stories with a similar premise. Evaristo does however, make her point (or the point I think she was trying to make); that "absolute power corrupts absolutely", that there's no such thing as a "good master", and that slavery is wrong no matter which way it goes.
A couple of things bothered me about the book. Evaristo depicts the white slave culture virtually identically to fictional depictions of black slave culture. Her slaves even speak a patois that sounds, when read aloud, very much like South Carolina Gullah (spoken by slave descendants on the offshore islands). I wonder whether white slaves would have developed the same patois or the same customs since they came from different roots.
These concerns aside, I did enjoy the book. Evaristo draws wonderful characters and paces her story so you want to read just a bit more, and a bit more, until the book is finished.