Great concept!
It's conveying a strange mix of moods: It's like nostalgia, but twisted into something darker, colder.
I really enjoyed that the stories alternated and intertwined at some points, so that the reader got an understanding of how different time is like and how strange this new way of living has to be for the characters.
All in all, I'd really recommend this book,
and I'm dying to know how the series is going to end!