As a ready reference, it does the business; at least enough to define the term, which one can research more if interested. The inclusion of historical figures; rarely-discussed lodges, orders, n and groups; and cross-referencing, give the reader a very firm foundation to understanding the modern occult movement in the West.
I sat down and read it through-- discovering the sources of now common, and popular ideas fascinated me because non-occult material fail to make that link. Thus, placing much more into its place of importance.
Obviously, it is impossible a single book to be perfect. There is a heavy emphasis on subjects relevant to the Golden Dawn and its inheritors. I would have hoped for more about recent movements, and developing ideas. Yet, with this one can easily understand any book published during and since the Occult Revival--which should have its own entry rather than squeezed into the occult history entry-- of the late 19th century. The article on Magic crams into a few pages, an exacting overview of the several meanings the word has had from ancient to present day theorists. Neo-Paganism does the same plunge to offer key points of developments, and changes.
A bit of a pet peeve that QBL, and all variants, are under Cabala. I do hold that the different transliterations act as a handy guide to the interpretations, and primary literature. Although, the author addresses this point specifically at the beginning of the article.