I will say I found this more enjoyable than the other two CoHo books I've read (Layla and It Ends With Us), the fact that it didn't romanticize abuse helped a lot!
I do find the trope of getting back together with your high school boyfriend/crush later in life super unrelatable, but it is what it is. 
A lot of the book was very predictable.
Clara gets super annoying and definitely doesn't deserve Miller based on the way she treats and uses him. 
Also I was really looking forward to seeing what was written in the letters, mostly because I'm nosey, so it sucks that it didn't end up going into that.