<p>Don’t go to Caltech if your goal is to be a premed unless you have a really excellent reason for doing so. Caltech is likely to make your GPA a few tenths lower than it would have been elsewhere, and while top PhD programs know this, med school admissions still seem to be run by a little pigeon that thinks a 3.8 or whatever is a magical number that means the same thing everywhere.</p>
<p>It’s easier to make yourself an easier schedule at MIT, so I don’t think an MIT GPA should harm your med school chances assuming you choose courses strategically and work hard. So, aside from not choosing Caltech, I’d go with the place that feels most comfortable to you.</p>
<p>(This aside, Caltech does have about 5 premeds per graduating class and the top two or so always go to the very best programs, both MD/PhD and straight MD. But these people are exceptional cases and it’s best not to count on being like them.)</p>