I voted "no" on helpful for two reasons.
One, the reviewer goes by a first name only. There is no evidence that it is even "his" actual first name.
This gives me the impression that something's not kosher. Given the subject matter, this is an inexcusable condition. The issue of credibility is the most important factor and it isn't fortified by "Moe" and "Joe" book reviews.
2) "Raymond" has contributed exactly ONE review - this one.
This is the classic indication of a "planted" Amazon review - one written specifically to do one thing - sell copies of the book. And of course, if this is the case, then suspicions inevitable arise that the review was written in exchange for compensation.
Amazon currently hosts MILLIONS of obviously phake product reviews that MUST have been financed by exceptionally well-financed & unscrupulous operations. Is this (the above) one of them?
I've seen the author on the news. He appears to be an honest man. Too bad I don't get the identical impression of the reviewer after having read the above.