I am in a similar boat too! I was accepted into the epi program at GW, Tulane, and Pitt. I moved to DC 3 years ago right after I finished undergrad I have a nice paying full time job, so naturally I applied to GW. I applied for Tulane too though because I want to go into infectious disease epi and have access to professors doing work in global health and international internship opportunities. I visited GW in October for their open house, and I just recently came back from a visit at Tulane.
At GW I got a sense from the students I talked to that even though it is doable, it is very difficult to work full time and take full advantage of the epi program. I also heard that the professors are not as available because are doing work else where and not only for GW. I did hear though hat there were many opportunities to work in DC and for other agencies, especially within the government. As far as living in DC, I love it, but it is dreadfully expensive, especially in Foggy Bottom. However, you can live in many other cheaper areas of DC, VA, or MD as long as they are metro (our subway) accessible, or you have a car (parking can be extremely expensive or hard to find however). Currently, I live in an OK but old, 800 sq ft 1-br apt in the Van Ness area of DC. It was originally $1700, but we "luckily" got it for $1479, which is a steal for our area. A lot of college students from AU and probably GW live there.
At Tulane, the program seemed to have a slight organization issue, but the students seem to love it there. The faculty members I talked to were extremely nice, and very busy on recently recieved grants. They seemed very open to working with students. I heard the program was challenging but very rewarding and students are more cooperative rather than competitive. There are are around 200 hundred students in the epi dept. 30-40 new students each fall. I was able to meet many students outside of the ones the program coordinator set me up to meet. They were all extremely nice, and I think I already met a couple lifelong friends! One of them had even went to GW for a semester and then transferred to Tulane and absolutely loves it. Everyone loved their program and advisor, and they all were currently working with a professor or at the LA Public Health agency, and not working crappy campus jobs. Outside of that, they said opportunities in NO and internationally were abundant through Tulane, which is good, since they require a 200 hr practicum outside of working with a professor. Living in NO is certainly different than DC. I got a chance to hang out with some of the students in the local areas and tourist areas, and I loved it! The bar scene is awesome. There are some run down areas, but you just need to know where to go. The public transportation wasn't as good as DC but Tulane has a shuttle system that helps. I was able to get around ok and I dont plan on having a car. If you are more laid back you will definitely like NO. It has definitely rebounded in many ways since the flood. Also there is warm weather in the winter versus cold in DC. However, the weather is extremely hot and humid if you stay in the summer.
All in all, I am leaning toward Tulane because I think it will be a better fit for me professionally for infect. disease epi, and also mentally. It has a laid back atmosphere that seems perfect for a college town and for the stress that will most definitely be incurred during the school year. Also, it seems easier to really connect with the professors and do meaningful research. Also, students and professors were saying that pretty much all students that graduate the epi dept easily land epi jobs, almost all of which are outside of NO. I still have to visit Pitt however, so we'll see what happens.