I've read tons of books about meditation and awakening and I've meditated for several decades with various techniques and methods, including the method which Adyashanti recommends here, which is based on relinquishing control and manipulation, and allowing everything to be as it is. My final conclusion is that (a) this is the best book on meditation that I've ever come across, and (b) the way of meditating which Adyashanti recommends is brilliant, and it works, i.e. it delivers the goods and goes far beyond what I have experienced with other methods.
I highly recommend this book both for beginners and for experienced meditators. Even if you're an experienced meditator, you will learn something new and helpful.