The BU law building is more like a dungeon.
i visited a few weeks ago.
while it is a very ugly building, some of the classrooms are quite nice. library sucks, looked small and ugly. BC had a nicer campus but i got more of a jock/bro vibe even at the graduate level, unfortunately (although for the undergrad thats a given). for what its worth, i'd rather be in an ugly building with a more professional group of students than a bunch of partially reformed frat boys.
no experience with tulane, though new orleans is a nice city. i prefer boston, but a drawback to boston is how homogenous the culture seems to be. i was shocked at how many white people there are, i've never seen anything like it, including the midwestern cities i've been to. obviously there are a lot of dominicans/purto ricans, but they seem to be segregated. besides that, and the cold, boston is great.