A relative of mine who graduated from Brown talks about the fact that back in his day, students would just intentionally fail a course if they thought they’d get a C or worse, because those automatically got expunged from one’s transcript, hahaha. Clearly, it’s not as ridiculous as that nowadays, but Brown definitely has the most “liberal” policies and flexible curriculum of any top school I know. For some reason, employers and grad schools don’t seem to mind all that much. Honestly, I think undergrad for med school is way blown out of proportion. A student who is smart and high achieving enough to get into Princeton would likely find great success at Flagship State U, let alone Brown and Duke (as they’d be at the top of their class). I would choose where you think you’d be happiest – that will probably have a bigger influence of your life and success. If you’re going by “prestige” only, I think it’d be hard to argue that Princeton doesn’t come out on top, but choosing for prestige only might not be the way to go in your situation. You really can’t go wrong. Congratulations and good luck!