James Wasserman, one of the most notable modern writers on magick and Thelema, has been reading a pre-release copy of Grimoire of Thelema and had this to say about it:

Rodney Orpheus, the modern Minstrel of Thelema, is back with another vibrant, creative, and irreverent effort that is sure to please and enlighten as it broadcasts the good news that the Lord of the Aeon is alive and well. This is a practical, lively, and meticulously documented manual designed for group magical workings. It admirably fulfils its task—bringing new insight to both published and unpublished rituals with diagrams and detailed instructions for movement, apparel, and Temple setup. It includes rituals from Crowley and others, and its important appendices round out an excellent work.

—James Wasserman, author of To Perfect This Feast: A Performance Commentary on the Gnostic Mass