I did not use any books besides EK (plus Princeton Review for psychology) and I did fine. I found that doing the questions at the end of each EK section helped me quite a bit, and reduced the need to take notes. The 30 minute exams in each book are also great -- unfortunately I left them until the end, and underestimated their difficulty. You could consider doing each exam 3-5 days after you finish the corresponding section as a way to review. Essentially, I think practice questions are the best way to study.
