Depends. When is the trip? What do you want to do/see? Do you like the beach? River rafting? Zoos? Gardens? Restaurants/Bars/Nightlife? Mountain drives?

That's a fair amount of driving between cities on some days. ATL-SAV and CHS-AVL legs are each about 4 hours.

The Sheraton and Aloft hotels in North Charleston are not downtown. Sheraton is a Cat2, so it's best redemption rate is on the weekends. But the weekends might be more crowded for whatever you want to see and do.

You'll miss out on Fifth Night Free options, so I'd definitely recommend looking for C&P awards.

The Westin Hilton Head would be a very nice beachfront stop between SAV and CHS.

1 in ATL (Cat2)
2 in SAV (Cat4)
1 in HHH (Cat4)
2 in CHS (Cat2)
2 in AVL (Cat3)
1 in ATL (Cat2)

If you want to break up the long drive from CHS to AVL, add in a night at the new Sheraton Columbia Downtown (Cat3).