I wanted to love this book as I loved the "Time travelers wife " . I struggled a lot in the beginning and nearly DNF'ed it. I could not pin point why I just could not enjoy this as much as I would have thought.   I saw a lot of negative comments about Adie and how her character did not make sense. 

That  she did not travel as much as she should, or grow as much as you would expect in 300 years.

That was not my problem with her. It took me nearly 80% of the book to figure out why I did not like this book at all. I just really did not like Adie. She was boring , selfish and just not very interesting. 

So why did I give 3.5? Because I think it is beautifully written. I think the whole book could be very enjoyable to read and very thought provoking. I like the way the timeline switched.  
The issues I have with it are only my personal preferences.  I like fast passed books with main characters that I find likable . I do not have to relate to them, but if I hate the main protagonist I won't be able to enjoy myself.