Tufts vs. Boston University vs. U of Rochester vs. NYU vs. Rensselaer Polytechnic Institute

I decide to study Mathematics as a major for about two years and then transfer to Computer Science within the same school. I confuse about which school to enroll since all of them are good school. Because I’m currently not in U.S., I don’t have a opportunity to visit every school, but I want people tell me about the true feelings of studying in each these schools. When making the choice, some factors might be considered, such as teaching quality of Math and SC, alumni net work, school’s atmosphere (or environment), and characteristics of classmates… Please provide me some suggestions.