I don't know if it's the book, or if it's just that at book 3 I'm getting tired of narrator. I found myself getting distracted very easily from the story. I may have enjoyed this more if I'd read the printed version.
I started finding the characters annoying, particularly Lachlan. I also found I didn't care much what happened to the characters.
I may give this series another go in print, but won't continue with the audio.