I passed the GWAPT (Sec 542) certification exam with the following study material:
SANS Sec542 on demand videos.
SANS Sec542 books.
Took each day 1 through day 5 quizzes multiple times (added the information not in my notes).
Practiced the labs multiple times.
280 page Index.
Failed both practice exams (68% and 69%), so I studied my weakest areas and went in the exam very worried, but passed with a 75%.
This is going to be my last SANS course/certification that I will take this year. Now I am going to focus on the AWS Solution Architect Associate and AWS security exams.