Well, good question,
but it depends on lots and lots of things: like who you are, where you come from, what your other strengths and weaknesses are, what your grades are, etc. Every little bit helps in general, so if you really believe you can get a 750, there is no reason for you to settle for less! It is true that if you hit 710/720 you are good enough pretty much to apply to ANY MBA program you like (although whether or not they will take you will depend on aaaall the other items in your profile too, as well as your essays).
Does this answer your question? If you want a fuller answer, feel free to post more detail, and I'll get right back at you, buddy.
If you like the post, give it a KUDOS!