I read every HCISSP book out there last summer, even the official cbk book for a total of three books. Then I attended a boot camp to review the course with the provided CBK course book and flashcards. Although the material I had read in the book prior to attending were great, the course book was more focused towards the test material and the practice exam we took was entirely different than any other questions at the end of every chapter that was available and even from the chapter questions from the course of the boot camp. It was another level of understanding that tested one's ability of the information, comprehension, and application. I honestly think I would have never passed without attending a boot camp, had I just relied solely on the material I read and research I did.
