3.5 stars.

The characters are likable and nuanced, and the storyline is really interesting; on a technical level this book is absolutely wonderful. But for some reason I just couldn't get as emotionally invested as I wanted to, and I'm not sure whether that was due to pacing, my getting caught up in the logistics and logic of time travel, the prose, or something else entirely.

Still, I wouldn't hesitate to recommend this to anyone who enjoys sci-fi and a good family story!