I passed the CISSP on 11/17/20 at 150 Q. I thought I'd share my experience because this forum has helped me in a million ways.
I started preparing for CISSP in July 2020 after completing SSCP in December 19. Fell off the wagon from August - September and started putting in 4-5 hours daily since October(I had been preparing for it for almost 5 months or so, but it was on and off.). I used to work till 5.30 then after taking couple of hours break and study until 11pm or 12am more or less. With a few breaks in the middle. I stayed on track for the most of it till I took the test. Rescheduled a couple times thanks to free rescheduling but finally decided on 17th Nov.
I will put my sources below and make sure to mention which ones were most useful to my success.
Take your time and read the questions carefully! You will be nervous; your adrenaline will be pumping and most of these questions have key words that entirely change the meaning.
1. Official Study Guide (10/10
2. Official Practice Exams (10/10)
3. Adam Gordon's accelerated CISSP course - 10/10
4. Destination Certification Videos - 8/10
5. Boson - 5/10
6. Study Notes & Theory ,Memory Palce- 8/10
7. Professor Messer - 9/10 -> recommended for D4
8. Discord - 8/10
9.ITDOJO - 8/10.
10. Random youtube & google search 9/10
11.Cissprep.net - 7/10
12.My own notes 10/10 📷
Everyone is different. Different instructors, materials, and video series are better at different domains.
The CISSP is a mile wide and an inch deep as they say. The thing about that mile wide... they can only cover about 5%-10% in one exam. There are thousands or tens of thousands of little details you may have learned in your career or memorized in your studies for this test. Most of it will not matter, they only have 150 questions tops and they're more focused on conceptual, big picture questions. They will ask you some granular questions that you'll only know if you memorized the little things, but 98% of it will not come up. I can't say that memorizing cryptography algorithms and key sizes *won't* help you, but just based on probability, a majority of the things you study won't show up.
Ultimately the study materials are not sufficient, and I believe they are trying to ask questions that go beyond "book knowledge but it is a very doable exam.
All the best.