I wound up with mixed feelings about Derek and Chloe. I continue to like how Chloe calls out the overused stereotypical plots of romance scripts, using those as a basis for making healthier choices. However, as a reader, and as much as I like tortured souls, Derek's fine line between angsty and verbally abusive sometimes slipped a little too much to the wrong side. I read this simultaneously with my 11yr daughter, and she said, "I like Derek, but I don't think I could be his girlfriend. He's too mean, even if he is screwed up in the head." 
 Some reviewers have said the book ends a little too unresolved. I felt the opposite - everything's all wrapped up in a neat little package with a very safe ending. With the overall darkness of the series, I might have liked an even darker ending. But I know I might be in the minority in that - especially in YA lit. 
 When everything is said and done, this series makes the reader think. My daughter and I had lots of "spin off" discussions about hard choices, growing up, how perceptions of parents change, rights that teenagers have (like the right to be taken seriously), how to handle jerky adults, boys and relationships, etc. We still talk about bits and pieces that happened in these books, and I love Armstrong for creating a book that provides opportunities for my daughter and I to come together.