If you are already a rosicrucian, this book will not help you since you have inside information. But if you want to read a true historian's view on facts involving the Rosicrucian movement, this is an excellent book. The author made a very thorough job of investigating sources.
His basis is veryfiable facts (not all facts unfortunately can be verified). He started writing on Rosicrucianism with the thought of it being a fledging unimportant movement, but had to change his mind completely as the many details came to the surface. This books covers everything from the Fama (manifestos) to present day rosicrucian movements like AMORC, and the Fellowship...
A very technical and scholarly book!