Yates' classic study of the 'Renaissance magus' Giordano Bruno left me with mixed feelings. On the one hand, the book is full of relevant information and insights into the world of esoteric thought in the Renaissance, and this makes it an essential read for students of hermeticism in the premodern period.
At the same time, I felt the work wavered a bit too much between being an introduction in hermetic thought from Ficino to Fludd and beyond, and being a biography of Bruno himself. I found the former tendencies of the book much more satisfying, because, despite an extensive series of chapters on Bruno, the true nature of his thought didn't come across convincingly.
Yates has been criticised in more recent scholarship for trying to force Bruno into a 'grand narrative' of renaissance magical philosophy, and this is also the impression I sometimes got while reading the parts about Bruno. For some reason, I felt Yates' story lacked argumentation, or at least that it did not communicate it clearly enough.
Regardless, the book is indeed valuable as an overview of hermetic and esoteric thinking, and its status as a classic work that would challenge scholarship of religion and history stands to this day. Yates may not have been right about everything, but she certainly stimulated a new generation of scholars to look at things from a fresh perspective.