Hi infinite87,
With your score goals, you're essentially aiming at a 700+ score. At THAT level, you would have to know more than just content - you have to know tactics, patterns, etc. that help make approaching the GMAT easier. The
OG is a great book for practice problems, but it's not built to teach you how to score at a high level on the GMAT. To that end, doing lots of practice problems is part of the process, but you really need to learn to answer questions in more than one way. The best Test Takers tend to be "flexible" in their thinking, so that on Test Day you can choose how best to approach a given question from a variety of options.
Right now, you're essentially "self teaching" by using a series of books. Most Test Takers get stuck at a certain level by working in this way, so you might want to look into investing in a GMAT Course of some kind (either Guided Self-Study or Instructor-Led). In this way, you'll have consistent, professional advice guiding you, teaching you tactics, walking you through solutions, etc. Most GMAT Companies offer some type of free resources (practice questions, Trial Accounts, videos, etc.) so that you can "test out" a product before you buy it. Take advantage of all of these free options, then choose the one that best matches your personality, timeline and budget.
GMAT assassins aren't born, they're made,
Rich