Hi JoeSeph,
First off, your prior 680/Q46 is a strong Score, so it could be enough to get you into your first-choice School. As such, a retest might not be necessary. Depending on the Schools that you plan to apply to, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your recent CAT score results - along with your last 2 Official Scores - show that you essentially performed the same each time (about 660 +/- a few points). You handle certain aspects of the GMAT consistently well, but you also make certain consistent mistakes. You're actually closer to a 730+ than you probably realize, but since you've been scoring at this same general level for some time, it's likely that you have gotten 'stuck' at this particular Score level. Thus, to earn a significantly higher Score, you will need to change how you 'see' (and respond to) the overall Exam.
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
1) What specific study materials have you used over the course of ALL of your studies? Which 'brands' of practice CATs have you taken?
2) When are you planning to apply to Business School?
3) What Schools are you planning to apply to?
You might also choose to purchase the Enhanced Score Report. While the ESR doesn’t provide a lot of information, there are usually a few data points that we can use to define what went wrong on Test Day (and what you should work on to score higher). If you purchase the ESR, then I'll be happy to analyze it for you.
GMAT assassins aren't born, they're made,
Rich