Just flip a coin... you couldn't go wrong with either. Other than that, find out what music is happening in each and let that be the tiebreaker. I don't know larger venues in Nawlins, but in Charleston, check the schedule for Cumberland's and Music Farm.
Edit: Oops... got curious and found out Cumberland's is no more.
http://www.last.fm/venue/8784512+Cumberland's
Cumberland's was a bar/venue in downtown Charleston SC. it was host to some of the best music to come through the area, and was a hot spot for getting your drink on. this year they shut the doors for the last time and the former building is now an apple store.