First of all, the whole story just kind of left me a little muddled and confused. It wasn't one of those stories where you're on the edge of your seat wondering what loop it's going to throw you through next. It was just a bit confusing and didn't seem fully thought out. Luce kept "realizing" things that I thought I already had figured out or I simply didn't understand at all even after she "explained" what she learned.
Luce. Luce, Luce, Luce. She drove me absolutely nuts! She was selfish and idiotic. She kept meddling with her past lives for her own benefit never once bothering to think she was intruding. She just HAD search through her past live's not willing to just accept Daniel's love. Every time she sees Daniel in a past life, though, she loses her head like a sex-starved teenage idiot. It's was beyond annoying.
The one thing I really like about Passion as compared to the other two was Daniel's POV. We got much more of it than the meager glimpses we've seen before. It was almost every other chapter this time. I liked to see what was happening from his end of things as opposed to everything being all about Luce.
Final thoughts: If you've read the other two in the series, then this one might be worth picking up since it's necessary if you plan on finishing the series. If you've never read the series, I definitely wouldn't recommend it simply because Passion doesn't have much going for it.