First off, this is an historical romance - and I usually hate them. But this one, I liked.
The characters are varied... there's the Austenian whining mother in the background, the decorative sister who, in a more poorly written book, would be nothing but fluff. In this case, though, she's clever, aware, and strong - much stronger than the heroine thinks.
The hero is a jaded fellow - rich and bored and trying to hold on to his moral compass. All he needs to revive him is, of course, the heroine. Oh, and there's a terribly black character who, in the interest of being different, is NOT the criminal (thief) of the story.
In all, I enjoyed this book. I would have enjoyed it much more were it not for the sex. I felt that there was no way a heroine of this calibre would just fall into bed, onto the floor, whatever, with the first dude that ever kissed her. She had too much riding on her to let him... stopping that analogy now. But at any rate, I would have found more chaste passion much more believable.