Leadbetter sure knows the golf swing, and has demonstrated that he can communicate this to others, evidenced by his renown work with some of golf's greats which he has helped.
I find myself in the group which highly respects Leadbetter, but finds that he gives too much. The many mechanical steps with all their relating swing thoughts and helps makes it far too mechanical and detailed for me, as well as for the likes of Bob Tway and Seri Pak who have chosen to go to more of a feel type help.
I find that John Jacobs stuff fits more to what I need from a help book, which can line up with what my ball is doing, and then offer advice to remedy it, rather than break down the backswing into ten steps.
To each his own. Many wiil find this of great benefit.