There are few things as intimidating as having the Java language architect review your book on Java (haha). It's a much, much better book thanks to his involvement.
He was very generous with his time and there are some good insights there for aspiring developers, as well as some info about the evolution of Java which may be relevant to the more data-oriented features that have been added in recent times.
While I'm normally not a fan of appeal to authority, knowing this is what moves this from "will try to remember to check this out when I wake tomorrow" (it's 23:04 here) to "will definitely check out tomorrow".
Also it being from Manning helps. It's difficult to find good books today, so easy to self publish or get reeled in by some paper mill that banks on people wanting to have a book on their resume. So have to have something to filter out signal in the noise.
There are few things as intimidating as having the Java language architect review your book on Java (haha). It's a much, much better book thanks to his involvement.