These are 3 pretty different programs. I will contrast them from my perspective, i interviewed last year.
location:
Houston- megalopolis. Crazy traffic but also every single big city advantage like lots of sports, bars, and culture galore. Beach is close but not really all that nice. Not a big fan of the city, but I know many who love all the hustle and bustle.
Charlotte- nice medium size city. Average bar scene and resturants. Mountains are pretty close and the beach is like 2 - 3 hours.
Nashville- cool city. Lots of entertainment, great bar / music scene.
Program:
Vandy- academic...very academic. Great teaching, very deliberate progression in clinical responsiblity. Ivory tower. Strong rep
CMC- community program with a decidedly academic feel. Well known. Really a great program judging from the recent grads I have met. Good mix of medicine and trauma
UTH- at "the largest medical center in the world." Has its nice hospital and its more urban aspect. Will see tons of trauma, inner city style. Residents work very very hard. Was personally not as impressed with the academics there, but all that was based on a one day snapshot and a few conversations I have had, so take that for whats its worth.