Those trying to decide among graduate schools should read this Brian Leiter post and follow its advice: talk to current students.
I'd add as secondary advice: beware of thinking that you can avoid the problems in a problematic department. Academia is in many ways a very solitary life, but grad students and faculty alike really are very enmeshed in the worlds made up by their departments and universities. All the problems he lists out there can poison a whole department. Be worried and careful if you find yourself explaining to yourself that the problematic professors/factions aren't in your part of the department and so won't affect your life as a grad student. It ain't necessarily so.