Wow. There's no way I'd live anywhere near 30 min away and actually go to school everyday. Maybe if attendance wasn't mandatory I would consider it, esp. if I had family 30 min away...but even still, I'd rather be close so I could go back and forth easily in order to study, eat lunch, etc.
I prefer to live close. Within 5 min...and preferably as close as I can without being on-campus. I only live about 15 min from my school now and I can tell you that the traffic, time spent driving and the worrying about parking is a huge deterrent for me and often the largest factor when debating whether or not to go to class.
IMO, living close reduces unnecessary stress on a daily basis, and anything to relieve yourself from stress during med school is great.