You do realize that you're basically asking if John meadows is competent, correct?
Let me answer that for you. YES. If you don't want to spend the money, that is fine, but don't get on here asking if John's coaching services are "worth it" because quite frankly it is likely offensive to John, as well as anyone who knows him.
Also, asking people what kind of "gains" they made is an irrelevant question, as there are a million and one factors, outside of coaching competence, that determine what kind of gains someone might make. A coach could have the best program in the world, but this doesn't mean that everyone who follows the program trains equally as hard/intelligently, eats as well, sleeps as well, takes the same amount/types of drugs, has the same genetics, etc.
Your question is no different than when someone asks what kind of gains they are gong to get from Dianabol. Questions like this cannot be answered accurately...because no one can possibly know the answer given the sheer number of variables involved.
The bottom line is that you either have confidence in John's abilities, or you don't. If you don't, then why hire him? If you do, then all your questions are meaningless.