I haven't written yet and plan to only write once.
My question was : Would schools still prefer the 720 even though it has taken the person 4 times ? over a one timer to get 680 ?
I'd say 490, 550., 700 is better than just 700.
This way you can show improvement and make an argument out of this. There is a whole bunch of kids out there with 700's but very few of them started out with 490 - it is a good chance to make a nice memorable story for the adcom.
I would say you have a stronger position with 490, 500, 550, 650
than with 680 or even 700.
I think progress and improvement are crucial. This demonstrates your persistence, ability to achieve goals, and work hard. If you can improve so much in GMAT, what about the areas that you are really good at?