I'd go strait through. We try and make it through about 10:00AM - 11:00AM and dont have any issues. You are able the use the HOV lane if you'd like and that can help sometimes.
My rule for I-75 through Atlanta is stay in the 2nd lane from the right. Anytime you merge with another interstate make sure to keep in the 2nd lane, the far right lane will usually end up being an exit only lane.