Thought I will throw my GMAT experience here. I have been a regular reader of GMAT club forums. I just saw a post about someone getting 690 and feeling devastated and thought I will write this.
I scored 690 in my GMAT. I wanted to go to Harvard/Stanford/Wharton and was of the opinion that anything less than 700 in GMAT is going to knock me out of the race for these ultra elite schools. I felt the same way when I got 690 and wanted to improve my GMAT score. I knew that the middle 80% is a broad range, but still I felt like 700 is a must. But I strengthened my other areas. I got admission at Wharton this year !!
Well GMAT is only one part of the application (well..I am not saying anything new here:). So don't worry about the 700 magic number (or any other magic number you might have in mind) and focus on the other parts of the application. Of course if you feel you can get 750+ and have been constantly getting above 750 in your practice, you can go for another shot. But as long as you are in the range of the GMAT scores for the schools you are trying to, you have a good chance..so do not lose sight over other parts of your app.
Good luck !!