I would have loved to have picked up stations of my hometown of West Palm Beach. I spent three days in Charleston, and stayed on the city's south side. My best catches were Myrtle Beach and Savannah stations, but nothing further. I figured Kiawah was a great spot, given how far it is from most of Charleston's big signals (except 105.5 and 98.1, as you mentioned). Most of my pick-ups on Kiawah were from Brunswick County, GA. Jacksonville's 102.9 was scratchy, but it was audible. Which Orlando stations have you picked up? XL 106.7?
I was also in Columbia, and was surprised how well G 105.7/Augusta came in. I thought more of the Charlotte stations would be clearer. The only really clear Charlotte station was 103.7 WSOC.
Finally, this was my first summer visit to Hilton Head, and there was a huge difference in the DXing between summer and late fall/early winter. The Charleston and Savannah stations were equally powerful. I couldn't get anything out of Jacksonville, however. I remember the jocks on WAPE used to claim that they could be heard in Hilton Head (I am not sure how that is possible, given WSSX's proximity!).