Another consideration is international profile of the student body. Responding to the LBS vs. Columbia J-term question, for example:
Columbia has New York, which I think is a big plus, since New York's optimistic mindset will show you that anything really is possible. However, Columbia is still 2/3 American. That's great if you want to work in the US or want to be molded in an American cultural crucible (a very empowering experience for Asian women, for example).
At LBS, however, no one culture dominates, which is a great experience for e.g. Americans unaccustomed to working outside the US, or for those looking to land in a non-US environment post-MBA.
Expect your MBA experience to mold you considerably. You will not be quite the same person when you emerge. Make sure the environment corresponds to the experience you're looking to shape you during the course, and prepares you for the environment you hope to work in when you get back to the workplace.