I'm almost in the exact same boat, I'm accepted at Tulane but wait-listed at BU (fingers crossed).
I have to say that if it comes down to it, and I have the opportunity to make a decision, I'll chose BU, however, that has a lot to do with my girlfriend who needs to be in a larger city for her career. I'm going to write a lot here, somewhat for you, but mostly for me to get some things out of my brain and down on paper (or LCD).
Tulane:
I absolutely loved Tulane when I visited, the city itself is so much more relaxed, and that leads to the med-students being better adjusted and not being as stressed or burning out any where near as quickly as in Boston. While the CoA may be similar, the actual prices of things in New Orleans are waaaaay lower than in Boston, you can get a great apartment in the garden district for a fraction of the cost of a tiny studio anywhere near BMC, not to mention that you can go out and have 3 beers in NOLA for the price of 1 in Boston. That means that while you're loan totals may be similar, your lifestyle will be a helluva lot better down south.
The community health and clinical opportunities at Tulane are phenomenal, I don't remember the exact numbers, but pre-Katrina there were something like 20 hospitals in NOLA, and now there are maybe 4. However, nearly 100 community clinics have popped up since, and those are run and staffed by students and doctors from Tulane. Tulane Med's president actually moved down there from Harvard after the hurricane with the specific goal of rebuilding the cities healthcare system from the ground up, and NOLA is rapidly become a national model for community health.
Not to mention the Murphy Oil Building, that clinical skills center was mind bogglingly awesome. I interviewed at 4 other schools in the similar range, and none of them came anywhere close to having a facility like that, BU's was limited to a couple of mock up rooms where you can talk to patients.
Great school of tropical medicine, I've spent the past few years working in an Immunology lab, and I'm definitely interested in taking my career down the ID path.
MPH program with no extra time for those who are interested (I'm not).
BU:
Tulane may have the community clinics, and the opportunity to see some tropical disease you may not encounter elsewhere, but having BMC as the primary training hospital is a huge resource. It may not be the flashiest place in the world, but it really is Boston's free clinic, and THE major trauma center for the northeast. You'll definitely see things in there your wouldn't elsewhere
New Orleans is certainly a decent sized city, but if you have any significant other moving with you (as I do), Boston offers so much more for other jobs. My girlfriend is a market researcher for a major ad company in NYC, she's willing to move, but it would be a huge career sacrifice for her to move to Louisiana compared to Mass.
Say what you will about the USN&W rankings, but BU moved up considerably this past year, and is top 35 for both care and research.
Tie:
Both schools emphasize the ability to do rotations abroad (something I was planning on doing where ever I ended up, but is particularly easy at these places).
Both cities have a great sporting identity to them, this may not be as important to many people, but the Saints in NOLA and the CelticsPatsSoxBruins in Boston are religions, a lot of fun to be around on game day.
Both are major research institutions with tons of opportunities to get wet bench experience.
Unknown:
How is the name recognition in the medical community and how are there reputations among residency directors? Does anyone know doctors from both who can make a comparison? I've seen the match lists, and from my preliminary evaluations, it definitely seems like graduates from both programs end up in all sorts of programs all across the country.
How are the financial aid packages? I haven't received it from Tulane yet, and won't from BU unless I'm actually accepted, is one school significantly richer or more generous than the other?
TL;DR version - Tulane is awesome, my heart is totally there, But I'll end up at BU if I get in.