My biggest concern was how easily Juliet overlooked the obvious truth. From the beginning, she believes that Gemma and Ben are the soul mates she is in charge of helping to fall in love. Since she is Juliet and falls in love-at-first-sight, complications arise when she begins to have feelings for Ben shortly after they meet. Her feelings for Ben begin to cloud her judgment, as this is the first human she has had feelings for since Romeo, and rather then help repair the relationships in Ariel's life, she starts to make things worse. I don't usually do this, but to better explain my frustrations I will have to leak a spoiler. So if you would rather not know (although, I figured it out 200 pages before Juliet so I don't know that its uncommon knowledge for the reader) I would move on to my next paragraph. How Juliet didn't figure out that Ben and Gemma were not the soul mates she was looking for is beyond my comprehension. It was very obvious that they did not have feelings for each other, and with Ben's reaction to Juliet from their initial meeting, how she could think he was destined to be with Gemma was just unrealistic. While I wasn't sure who Gemma's soul mate was, I knew it must have been someone else, and that it just couldn't be Ben.
My other problem was with how quickly Juliet found herself in love with Ben. Yes, I realize this is an extension of Romeo and Juliet, but after being hurt so deeply by Romeo's betrayal, how she could trust her feelings so quickly was just annoying. And Ben! He was talking about how he could see a future with her, marriage and children, after only knowing her for three days. I just had no sympathy for Juliet's predicament (she was forbidden to love a human since she was merely borrowing some other soul's body temporarily) since I couldn't understand her feelings for Ben (or his for her). The reasons he listed for being in love with her were all things one finds on the surface, and she merely felt a spark of recognition and an instant connection - neither of which are the basis for a real relationship.
Gemma was a confusing character. She was so friendly and charming in some chapters, and then in others she was a cold-hearted bitch. Her moods seemed to change quickly and without explanation. Romeo was similar, but I understood the reasons for his actions - he was doing anything and everything possible to make Juliet believe his version of things, as he believed it was the only way to get his body back without having to renew his vows to the Mercenaries. As he slipped further into madness, I found myself getting more and more angry with Juliet for turning to him for answers. Someone that desperate will say, or do, anything to get what they want. And I really wish we had gotten to see more of Ariel. She was mentioned mostly in passing, as Juliet dug for one of her memories, but her story seemed more interesting then a lot of what was happening.
I loved Juliet's ending, even though it was a happily-ever-after type ending, I don't feel like Gemma necessarily deserved the ending she got, and Romeo's ending went from being too harsh to too lenient.
Overall I enjoyed this book, but I don't know that I'll continue with the series.