I passed the exam (July 2018) and received my endorsement!
This was one of the tougher exams I've taken. The toughness of the test was primarily due to the lack of official study material for the updated test, and the small group of people currently preparing for the certification.
The exam definitely follows the ISC2 approach of ensuring you have full understanding of the underlying topics. The questions test your ability to apply your core understanding and I do not believe there is a way to study for the questions. Rather, you must truly understand the material at a core level.
You need to ensure that you completely understand the core CISSP as well as the extended ISSAP depth of questions.
Where the CISSP is "a mile wide and an inch deep", the ISSAP is 1/2 a mile wide and a few feet deep.
The following is how I approached studying for the test:
Read the Official (ISC)2 Guide to the ISSAP CBK - 2nd Edition (I read it once cover to cover with a mind to detail. I read it once focusing on any areas where I could not immediately remember the details. I read it a final time to brush up and verify my understanding of each area)
Read all online documents identified in the ISC2 CBK chapter bibliographies
Read all online documents identified in the ISC2 CBK Suggested References for the ISSAP (I did not purchase any books other than the ISSAP CBK)
Downloaded the ISC2 Exam Outline for the ISSAP, searched for, and read, references to each section (focusing on NIST documents, Whitepapers, and RFPs)
Downloaded and read the Jake Eliasz CISSP-ISSAP Loose Notes, thanks Jake!
I also revisited the CISSP study material (Sunflower Study Guide & the Shon Harris CISSP All-in-One book, specifically the end of chapter Quick Tips) Test Question Preparation
I utilized both the ISC2 CISSP & CISSP-ISSAP phone apps to run test questions.
Taking the Test:
You must be focused and relaxed.
I started by doing some deep breathing exercises and repeated those about every 25 questions. This helped me relax, focus, and take my mind off the previous set of questions.
Read the question. Read the question again. Read the question a third time.
will be following your study guide, and am happy I stumbled on your post, planned to take the exam after going through the official ISC2 ISSAP self-paced training, (a shame I could not finish it within the allocated time). Plan to take towards June ending