Definitely not the west route. Depending on the time of day (not before 10 am or after 3 pm) I would go straight through downtown on I-85. 285 around the east side not too bad either during those times. There is insignificant difference any more between the routes except NEVER try 85 through town after 3 pm. WSB radio FM 95.5/ AM 750 has decent traffic reports.
Your biggest problem will be unable to cruise at 80 mph. At 65 mph you are a rolling roadblock. I just ignore the speedy ones and let them figure out how to get around. Avoid the far right lane...people around here still don't know how to merge from an entry ramp.
Hint: Fuel up in Alabama with enough to get you into South Carolina. Georgia has high fuel tax.
2018 Forester 3051S (aka Clyde)
2015 Wrangler Toad (aka Bonnie)
At some point during every day you suddenly realize nothing else productive is going to happen the rest of that day. For me, it usually occurs around 9 am.