There's no guarantees someone scoring 750+ will get in, as MBA admissions committees take a holistic approach to the admissions process. Using the same holistic approach, they're not going to automatically ding someone who scores a 650. Although a higher score can obviously help negate other weak parts in an application, it's not a make or break issue.
Unless you are a Mckinsey Consultant/ GS Analyst a 700 is sub par for Top 10, you may get in but remember there will always be people with better profile and slightly lower GMAT score than you. The only way to take the GMAT out of the equation is to get a 740+.
Spring has passed, summer is gone and winter is here. And the song that I meant to sing remains unsung.
For I have spent my days stringing and un-stringing my instrument.