I have read every JR story from Lee Child.
Blue Moon is very disappointing. The book is thin and similarly so is the plot short on credible detail. For me perhaps his best book so far was The Midnight Line.
Blue Moon has the identical formula to every previous story expect it is far sketchier with the reader left to fill in so much detail that would have been written in previous stories. This has led me to the sad conclusion that Lee Child has either got bored and is writing to a formula to the extent that he can't be bothered to fill in all the previously greatly researched details, or this is the work of a ghost writer.
Sadly not his best work.
N