"A Customer" was clearly expecting a step-by-step self-help book, which is exactly what this book isn't.
While it does offer instruction in bringing about the relaxation response through meditation, there is also much supporting medical evidence, and examples of the approaches taken by practitioners of different religions through time. The idea is, of course, that you can take or leave whichever bits appeal to you, and it's emphasised repeatedly that meditation needn't be a faith-related activity and can be undertaken by those who are entirely godless (my words, not the author's!)
Overblown guff? Not at all. Stating the obvious? Up to a point. But it's so much easier to accept the necessity or usefulness of doing something obvious if it's backed up by some well-reasoned argument.
This book will take just a few hours to read unless you're a really slow reader, and if, like me, you've suffered from chronic depression I'd certainly recommend it - but as a complement to drugs rather than an alternative.
I've given it five stars for its potential beneficial effects; if I were to be hyper-critical, I don't much like the prose style, but it's easy enough to read. And in any case, it scarcely matters that the book isn't great literature.