<p>If you are really torn between two schools, you should not apply early decision to either of them. Early decision is, in my opinion, very overused. It’s an option that’s really only for students who are 100% sure (or at least 95%+ sure) that they want to attend a particular school AND 100% sure that no matter what kind of financial aid they get, they can afford to go there. I know that people will tell you one can get out of ED if one cannot afford the school, but the school will be the one who determines whether you can ‘afford’ it or not.</p>
<p>Just apply regular decision to both schools, and that way you can decide in April or May which one is the best fit for you when you have ALL the information you need, including their financial aid packages. (Just guessing, but you may get better aid from Vassar).</p>
<p>I will also go out on a limb here – I go to a medical center right now as a graduate student (I’m not in the medical school, but the top 10 medical school and my top 10 public health program share a campus that is part of a larger university) and not all medical schools (including top ones) have extremely competitive student bodies. You don’t need to go through hell in undergrad to teach you to cope at the medical level. The students at my center get along very well, help each other out, and hang out with each other on the weekends. It’s not cutthroat at all, and some of them are more relaxed than the Ph.D students 
You can be dedicated and driven without being cutthroat and competitive, and sometimes it is in your best interests to play nice.</p>
<p>Both Vassar and JHU can get you into the same medical schools. Really, it depends on you and what you do. I know people who went to my little tier-2 LAC in the South who are now at Harvard, U-Penn, Wash U and Yale medical schools. It depends on your hard work and what you do in undergrad, and you sound like you would be more comfortable at Vassar. But I really recommend that you don’t apply ED anywhere because you don’t sound 95%+ sure that you want to go to either of those schools.</p>