This one didn't really seem like Selena and Trez's book. It was, but at the same time, I was more invested in iAm and his female (not giving any thing away). Trez and Selena don't get a happy ending, which really isn't a surprise but it still think it's a little unfair (Jane's back, after all). I'm betting there's something going on there. The next book is about Mary and Rhage. I kind of expected it, since there is quite a bit of focus on the two in this one.
This series is just getting bigger and bigger. So many POVs, so many different things going on at once. I don't mind a little set up for the next book but the last few of this series have had the other characters taking over the book and the main characters get lost in the shuffle.