I enjoy reading the novels in this series. Like the previous three books in the series, Broken Harbor was a quick read in which I could lose myself for a few hours. The plot stretches the limits of credibility in some spots, but I'm pretty much okay with that. The "murder detective haunted by his/her past" trope is growing a little stale (can't anyone be influenced without being haunted?), but not yet stale enough to turn me away from the series. 
 In this one, I particularly like French's picture of suburban living, the pressure to conform, and the dark side of positive thinking. I wonder if the focus on class would work as well if the novel were set in the United States. We certainly have class divisions and class-based stereotypes, but I'm not sure they're as exaggerated as they are in French's Ireland. For example, I don't think I'd necessarily be able to tell someone's social or economic class based just on their accent. But then, maybe that says more about my knowledge (or lack thereof) of accents and than it does about class divisions in the U.S.