The quant core is solid, 45 is kind of a threshold score where quants programs would not have any concerns about your ability to keep up with the quantitative courses.
The 59th percentile well that's to be expected because quite honestly you competing with ethnic groups that are quite known for being math geniuses. The fact that you're not a math genius doesn't mean that you'll flunk out of the classes, and they will realize that.
So if you are planning to apply this year and you're trying to decide if you should focus more on the GMAT or write your applications then I would say definitely focus on the applications.
However if you are thinking about applying next year and have time, may as well keep up the momentum to tack on another 20 points to that score which can never hurt and will definitely put you in a better steed with elite schools, and all schools really.
So bottom line, this score won't keep you out of schools, but a higher score will of course position you for even better odds.
At the same time your application is equally important. If you're going for round two this year we don't want to rob Peter to pay Paul here.
Farrell Dyan Hehn, MBA
Admissions Consultant & Verbal Strategist MBAPrepCoach.com