Both schools are great in the area OP is looking into. I'd advise against choosing a school just because of its name, especially at the level of Berkeley and MIT. The name of both of those institutions go very far. I've visited both schools (and even spent a summer at one), and I wouldn't say MIT is any better or worse. I've met quite a few grad students who turned down MIT. It really comes down to personal fit.
OP: Did you not have a good match with faculty members you talked to when you visited MIT? Maybe you could spend more time looking through their webpages and emailing/calling them. I'd imagine you had a few professors of interest when you applied to the program, no?