I really liked this book because it explored a character that has always been known as evil and showed he was just human. Mordred has issues and those issues are brought to light in the book and not just brushed over, but they are issues you can sympathize with. I liked how the author explored everyone's hand in the downfall of Camelot and not just Mordred's. It's always easy to place the blame on one person without looking at the actions of others, regardless of how heroic you claim them to be. I actually found myself disliking Lancelot in this book (when normally I don't) and thinking of Arthur as bit of a wimp.
My only dislike was that it didn't explore Mordred's feelings enough. I came away not really understanding how he felt about the three women. This could be because it was written for YA and the author didn't want to go there. Maybe I am just used to my romance novels and so this left me feeling a bit empty.
If you are not open about the Arthurian legend you might not like the book. However if you enjoy exploring all angles, I think you'll really enjoy this book. I did. It's an extremely easy read.