Number one shortfall IMO is no supercharger in Charleston, SC. With a million residents in Metro Charleston this has to be the largest population center still w/o a Supercharger.
FWIW I have used dozens of SC locations across the southeast and have never had a problem finding a restroom nearby. I do tend to drive during the day and sleep at night so this could be a problem for those who drive overnight.
When I planned a trip to Charleston last year, I was surprised not to find a supercharger spot there. I had to stay at this hotel in order to charge: TownePlace Suites by Marriott Charleston Mt. Pleasant.