Tough decision with a USD20K scholarship...
Last year a friend of mine (also Brazilian) got also 20k, and he also got into Wharton and MIT, and he's didn't have >700 GMAT (I think it was 670 or 680), so I believe is more the strategy that Ross is developing its name in some parts of the Globe. He decided to Wharton, but did so, because money is not a problem for him, he comes from a very wealthy family. In my case, 20k would be somehow a decisive factor.
Anyway, no one can't go wrong with Ross, it's a very good school, strong brand in US (and improving in other places).
If I had some more options, I'd visit the school, the places nearby to take a more solid decision.
But hey, tough decision, but a GREAT ONE!