Played Old South a few days ago. The course was in good shape and fun to play. Some "different" holes that require you to lay up with a long to mid-iron and then hit your approach shot to the green. The course was mostly fair but I would use the 18 Birdies app or something else to show you the satellite view so you can identify where the trouble is on each hole as it is not always apparent. Greens were slow but there was a LOT of rain the day before.
We played Old South with another couple who had played Oyster Reef a few days prior. They liked the course and commented on how fast the greens were when they played.
We wanted to play Hilton Head National but we were rained out
. Have a great trip!