First, be doubtful whenever someone tells you "all the ppl I know that did that are in the bottom 1/2 of the class." Unless their school publishes the names of individuals and their class rank, it's doubtful that they actually know how well they did. (You'll soon come to find out ppl lie about their grades a lot. More ppl will claim to have received A's than profs actually give out. Some ppl claim to have done better than they probably did, just as others are modest). Second, there are ppl who also wrote out their briefs and are also in the bottom 1/2 of the class. I wouldn't count on any particular method to give you an absolute advantage in exams. Through preparation and good application is what gets ppl good grades.Lastly, book briefing does have an advantage when it comes to being called on in class. It's easier to find the non-emphasized case cited by the court when you highlighted it in orange by flipping through the pages looking for orange rather than all of your notes and the case while the whole class waits for you to answer.In the end, your grade is dependent on an exam, not how you prepared for a particular class. Taking notes in addition to book briefing is IMO the best method for class preparation and outline preparation. How you perform on an exam is dependent on your own capabilities.