I wavered between 4-5 stars, wish we had that 1/2 star, but it had too many of my favorite things to be a 4 :)
As my GR friend Juliana pointed out, it had mostly everything I love in a good HR:
1) Emotionally damaged hero
2) Bad boy / Rake
4) Strong spinster heroine who saves bad boy
It also had a good plot and lots of sexual tension. Some of the big plot issues were silly things that were very contrived just to make the book work, but it is fiction so we expect that :) My only issue is that he is supposed to be this big bad rake, but I found nothing really rakish about him other than he wanted to get h to be his mistress. He was actually a very honest and honorable man.