If i were you..I'd 'settle' for 700.
I think 700 represents a number good enough that you can handle the heavy 1st year coursework in any top schools.
Imagine the pressure you'd put yourself knowing you need to beat 700 again for all your 2nd go round prep, gmat $, and time to be worth something.
I know there's another side where they always say it never hurts to take it again because if you're going to finance/MC firms your Gmat will be asked again by recruiters.. and schools always say that they will only look at the higher score.
Sometimes I'm not too convinced with this, because adcoms are humans and if they see that you went from 700 to 650 (So they will wonder which score is the fluke score)... hmmm.. I think they rather see 1 score with 700... or 650 to 700.
This is just my opinion though. I don't know if they really think of it this way..or it matters as much as it is.