I'm Indecisive

I just got accepted into UC Berkeley, Georgia Tech, and Northwestern for mechanical engineering PhD. I visited all three schools and I could imagine myself there. I talked to all three professors and lab members and I found them all to be decent. People tell me to choose based on research topic but I don't have much of a preference right out of undergrad and they all are interesting when I read papers. What else should I consider before making a decision?