I'm a CISSP too, nothing I read in the ISC2 study guide prepared me for the test. I have 25 years in IT and 5 years building Cloud Security and transport. The book I read did not prepare me at all for the test and its ISC2 Official Study guide.
In order to pass this you have to learn to take a test with trick question. This is a total waist of time and now I must be done again and they will get more $$.
-unLucky
With twenty years in IT, though comparatively smaller time specific to IT security, I read:
CISSP for Dummies
(ISC)2's CBK by Alan Gordon
Mike Chapple's CISSP Study Guide (8E)
C4D was a waste of money, but it introduced me to the wide-ranging variety of disciplines.
CBK seemed unwieldy and organized, but it was fairly definitive.
SG8E was the book that tied everything together.
Passed first time, but I must credit Craig Cunningham for his boot camp. What appeared as words on the pages of three different books became three-dimensional structures in his class.