Stayed 3 nights in the Hilton Garden Inn Downtown for a conference at the GWCC, very happy with the service, location, room, cleanliness, sleep quality. Only small detail to improve would be gym that is on the small side with only two treadmills.
The Aquarium is just around the corner and the GWCC two blocks away, walked there several times also at night, no problems.
Room large, clean, new, wifi complimentary. Front desk service very good, taxis always available. I did not try the pool but looked nice. Breakfast nothing special but at 11.95 good value.
Room rates reasonable, good value. All in all, a great place to stay for downtown Atlanta, can recommend it.