I'm local to Boston area - Boston and Cambridge are great towns for college students. Moderately sized city, with lots of student focused activities, because there are many schools in the area. (BU, BC, Northeastern, MIT, Emerson, Harvard all within a few stops of the subway of one another, and some within walking distance). There are many more than those.
Tufts is just outside of Cambridge. You can catch a bus to subway/Cambridge, and easily get to all that the city has to offer. Tufts itself is an area that is urban residential. Nice campus on a hill, great vibe.
My D. visited the school, liked the energy and thought people were engaged and mellow, if that makes any sense.
Downside of the area - you are in a city, there can be crime. It's New England (brrrrrrrrr).
Browse through some of the posts on the Tufts section here at CC to get a flavor of the place. http://talk.collegeconfidential.com/tufts-university/