What sets NUMEROLOGY... apart from other books in the New Age/occult sphere is the quality of writing. It manages to be both straightforward enough for beginners while engaging enough to keep an adept's interest in the material. The book establishes a very straightforward system, adequately explains each and every association within it, and incorporates tarot, the Bible, and astrology into it in a surprisingly comprehensive fashion. At the same time, it never feels like Bunker repeats themselves unless it's absolutely necessary-- it's surprising how few spiritual books that can be said about! The weakest material is actually the titular Divine Triangle; it's an interesting concept, but doesn't really feel completely thought out at heart. Furthermore, I would have liked to have seen a bit more exploration into the methodology behind assigning zodiac associations to every number.
I don't believe in Christianity, karma, or reincarnation, so I more or less read the book as a skeptic. It's been four years since buying my first copy, and I still find myself frequently referencing it or (re)calculating some of my own personal "vibrations" for one reason or another. The paperback has wide margins, which means there also is plenty of room to work out the numbers on the side if need be.