It's a very concise book for the most part. The only thing that i would have liked to see is some resources so that the reader can do their own research and draw any conclusions they might have.
The information about the phantom hounds was interesting, although there was no specific instruction on how one might attract/summon said hound. Would be interesting, don't you think?
The exercises designed to develop awareness of our surroundings is the most important to me, because i feel that many people walk around in a sort of trance and it seems that they have a hard time externalizing awareness and noticing what's going on around you. We miss too much. These exercises can help a person notice when someone intends to do them harm or is attracted to them.
The exercises on astral projection are informative, however, for most people who don't have a clue as to the working of the conscious, subconcious, and super conscious minds ( edgar Cayce, Huna), then astral projection is a hit or miss thing.
Overall, it's a good book and for anyone that wants to TURLY understand that book and put the information to use for your own purposes, whatever they may be, then you'll want to check out a few books that sort of Phil in the blanks:
"The laws of psychic phenomenon" By Thompson Jay hudson
Anything By CW leadbeater and Annie Besant
Anything by Donna Eden (more information on the chakras/aetheric links)
Anything By Frank Randolp Young(Psychic/mental influence)
Anything by Walter William Atkinson
In addition to the resources above, there's a wealth of scientific research that validates psychic influence and the existence of the chakras, two books that come to mind immediately are:
1) Experiments in distant influence
2) Experiments in mental suggestion
There are countless other resources out there for you to study.
Overall, it's a good read and there's lots of useful information, especially the breathing meditation, which is essential to performing the experiments/tasks in the book.