If you're talking about university alum network generally, I agree that Michigan, ND, etc., have wider networks. But if it's legal network specifically, BU law has around 20,000 alive alumni, which is probably among the 10 largest. There are alum associations and events even in California. However, with any networking activity, you'll have to meet 50 people to get one that is helpful to your career. In the end though, I think more alums mean better chances of an alum reviewing your resume or interviewing you for a position. Boston, NYC, DC (and to a lesser extent, CA) firms are packed with BU/BC lawyers with somewhat similar numers. That's why I would say that BU/BC students face very similar employment prospects all around.