From a personal standpoint, I loved this book. It was a perfect dose of escapism and exactly the kind of fast-moving, not-terribly-deep novel I needed right now. As such, it’s a 5/5 for me.
That said, I found the plot pretty convoluted and improbable, so if I think too much about it I kind of roll my eyes at the twists and turns it took. From that standpoint it was a good solid 3/5 for me.
… and so my final score is a compromise at 4/5.