You’re right in Atlanta at Emory. Not downtown, but well inside the “ring”. Atlanta is a bigger city than Philly (geographically), not as densely populated. It’s also growing, while Philly is shrinking (in terms of population).
I do not prefer one city over the other, but they are both major cities.
Also, depending on what kind of Poli Sci interests you, Atlanta is the capital. Philly is a couple of hours from Harrisburg.