I would prefer the route going toward Valdosta from Albany, hooking into I-75 not far from the Florida border. It would give traffic coming from the Jacksonville area just as direct an Interstate quality route as upgrading GA-520/US-82 to Waycross and going down to Jacksonville via US-1. And it would shave off miles for traffic heading to/from Florida's Turnpike (Orlando, Miami) and I-75 (Tampa Bay area, Naples, etc).
I think GA-520/US-82 does a good enough job as is serving Brunswick, GA traffic, even as a hurricane evacuation route. Not many people live in that area and the visitor capacity on Saint Simons Island, Sea Island and Jekyll Island is somewhat limited (maybe even on purpose since some spots are a bit more exclusive to those with deeper pockets).