One thing to remember is that Qbank is not really reflective of the actual exam, so if you find that you are guessing a lot on questions that test nit-picky details then that should be okay (those types of questions are more likely to be experimental on the boards). On the other hand, I can almost guarantee that you will walk out of the exam feeling the same way as you feel about the Qbank questions--I know I sure as hell felt horrible. You just have to remember that you did great on Qbank (72%!) despite that feeling, and thus will probably do quite well on the exam.