@Rahul: As per your request, I am giving my opinion.
First of all, congratulations! It certainly is a good score.
That said, I would be more comfortable applying to ISB with a 750. Not that it would give my chances a boost but I would have nothing to worry about losing out in 'GMAT score' aspect. Among Indian applicants, 750 is kind of 'normal'.
But then again, there are no hard and fast rules. If you can manage to produce a very good application and crack the interview (your long experience will be very helpful), a 700 is good enough. Rather than going back to GMAT prep, you should spend your time sorting out your story and figuring out what differentiates you from the next person, what unique characteristics do you bring to the table, why the school is a good fit for you, what you intend to gain from the school, what you can give back to the school, why the school should choose you over the guy who has 750, great acads and a good work ex. In my opinion, they will focus less on your acads and GMAT and more on your work ex (which has to make you shine).
Even if you do want to think about re-taking GMAT, consider this: Did you prepare well for it? Do you think you can improve markedly next time or will you rely on luck to take you 30-40 points higher? Do you know your weaknesses and are you sure you will be able to put in effort to work on them? Also, do you feel that luck played in part in reaching 700 or do you think that you deserve not only 700 but also more? Retaking GMAT doesn't reflect poorly on you but if you score around 700 next time too, it might show that you are re-taking in the hope that you will get lucky sometime. If you do take it again, it has to be for a marked improvement. You should touch 750 to show that you did not perform up to your potential the first time around and hence took it again.
I agree, that is very good advance. I may even follow a bit of that myself, though it wasn't directed towards me lol.