Well, first of all Vandy is only going to take a certain amount of people rotating with them from July to October. Maybe what, 5 or 10 a month. So you can't all go there anyway.
Second, I have no problem with you learning a lot on an EM rotation. My suggestion is you take the mindset that you're going there to show what you already know, not to learn. Of course you're going to learn something too, but it's an audition. Everyone you interact with is looking at you and saying to themselves "Do I really want to work with this chump for the next 3 years?" Show up early, stay late, be social, be a strong student (what's that House of God rule?) etc. More than anything else, you need an honors out of that rotation. Because even if you don't go to Vandy, everyone else gets to see what Vandy thought about you....it's in the grade.
I'll tell you what I did. I did 3 EM rotations, one in the Spring of my third year at a community hospital/trauma center in the same town as my medical school. I learned a ton and cemented my desire to do EM. By April of 3rd year I knew what I wanted to do, which helps a lot compared to not knowing in September. I worked hard and must have impressed someone because I got an honors. The competition for honors, however, was lower than anywhere else because they just don't get that many students interested in EM. My second rotation, August of my fourth year was my home institution which at the time didn't have an EM program. This was primarily to get an honors and SLORs. My last rotation in September was at an away program. It was purely an audition rotation. It was a bit weird because it was a program I didn't want to go to, but because I had to go through the military match, I had to convince some military folks that I would be a great person to match into EM, even if I wanted to do a civilian program. The competition among students at this rotation was far higher than anywhere else. We knew we were going head to head and we hadn't known each other for 3 years already. In the end, I got honors in all 3 rotations and when combined with what must have been okay letters and stellar board scores, I could pretty much write my own ticket for interviews (I was invited to interview at 28/30 places I applied- screw you UNC and Madigan!) I had a friend, same school, similar background, similar board scores who got a "high pass" out of his rotation at the home institution. He was turned down for an interview by many places I got an interview at (basically every 3 year program out West) and ended up matching at a solid, but not particularly competitive, program in the Midwest. I think I ranked the program he went to 12th or something.
If I were a more typical med student, I'd do the same order, but replace that last rotation with someplace I really wanted to go, but thought I might not get an interview at. Then I'd bust my tail all month. A "high pass" isn't a death sentence, but don't pretend it doesn't matter.
