As a local, I would suggest that you stay somewhat near your business (assuming that you are travelling on business) since traffic in the Atlanta area can be pretty bad during rush hour.
Having said that, if you want to stay within the city I would avoid the downtown (unless that is where your business takes you) area which would include the Marquis. The Midtown area, which would include the Marriott Suites and a couple of "historic" Residence Inns is in a more hip part of the city. Buckhead, which would include the JW at Lenox and the aforementioned SHS is the more fashionable area of town nearer the higher end restaurants and shopping. The suburbs are pretty spread out and if you were to choose a property there, it would be based on proximity to your business.