I have visited a few different universities throughout my Ph.D. program application process. I am also an international student myself and studying Statistics. While I have not received an offer from Brown, I have received offers from Berkeley and Georgetown. I would think it's best to go to a program that is highly ranked rather than just ivy. While it is nice to have a school on your cv that is in the ivy league, what difference does that make if it is not highly ranked with an amazing reputation. These programs have also been around for much longer and would offer you greater opportunities down the road. If the only thing that Brown has to offer you is that they are in the ivy league, I would not go. I would rather go to a highly ranked program that will afford me a better chance to get a well paying job after I complete my degree.