I never interviewed at Tufts but being from MA, I can tell you a little bit about Boston. Just take into account that I haven't been back to Boston in 5 years!
Boston and Baltimore are both very small cities (compared to NYC or LA, etc..) Boston is very Irish... the nightlife revolves around pubs and sports bars, (not my thing). If you're into the clubbing thing, there is a street full of clubs, though if you're used to NYC clubbing, they fall very short of expectations! The people are very intellectual and academic since there are so many universities and graduate/doctoral programs there. The style is either laid back, (jeans, t-shirts and sneakers) or very preppy, (Gap)... There is a decent amount of cultural activities... Beaches are nearby in RI or Cape Cod...
As for Boston housing, if you live near Tufts, you'll most likely be renting a room in a very old house, (again, not my thing).
I spent a total of 22 hours in Baltimore but my overall impression was good. It seems like a small city, about the same size as Boston. The west side where the school is located is beautiful. I know Baltimore has a bad reputation for being just an industrial city and quite dangerous, I didn't see anything like that. The school is nestled in a downtown area with tons of high-rises near the inner harbor which is filled with restaurants, clubs and museums. The housing options near campus are mostly luxury apartments/lofts all with a $800-1100 rent range for one person living alone. It seems like the nightlife is pretty much like Boston's with lots of sports pubs and few dance clubs... but I can handle that since I'll be studying most of the time anyway!
The dental school in MD is what really impressed me. It's part of the UMB campus which is where all the graduate programs are: Law, nursing, medicine, biomed research etc.. etc.. etc... While the dental students don't take classes with the medical students, most of the science faculty is the same. And since UMB's medical school is pretty highly ranked, I'd assume that IF dental schools were to be ranked, it'd be pretty high on the list as well. Also, the dental school is #2 in the nation for NIH funding, which speaks very well for the school.
The new building will be hands down the best facility in the nation once it is finished. Even the old building wasn't that bad... there was ample space for clinics and there seemed to be LOTS of patients there.
The faculty I met were all amazing... and the students were cool for the most part.
Quite honestly, I thought UMB dental was the best dental school of all the ones I saw: Columbia, Nova and UMDNJ... and of course UMB
As another poster suggested, I'd visit both schools. Honestly, I couldn't afford to travel to that many schools either but I sucked it up and put my trips on my credit cards. And I'm so glad I did because when I began my interviews, UMB was at the bottom of my list, and also the most expensive trip I took. I almost didn't go and am SOOO glad I did now!
If you have any other questions about MD, feel free to PM me