I would easily take Vanderbilt over UCSD any day... I did an away rotation there during MS4 and I absolutely hated it.. felt super cliquey, everyone seemed kind of on edge... not to mention, cost of living in SD is ridiculous, and they are consistently sliding in rankings every year. I have a few friends at Vandy, and while I did not do an away rotation there, I've been in the medical center a few times and people are super nice and you feel a very warm and inviting southern charm... also, people in Nashville are very genuine and easy to get along with from my experiences... obviously this is all anecdotal and my experiences may not apply to you, but from the few friends I have who are med students or residents at UCSD, not the best place to train from a social aspect