Thanks everybody for your advice. I will go and take a look at The Glenn. My lunches will be at the conference, but dinners will be my own choice.
The conference itself is at the Georgia World Congress Center, so it would be an easy walk from the Glenn.
I agree that Midtown has a lot of nice places to eat. Good to know about MARTA. It was not that reliable for me last time I was in Atlanta. Too bad it has gotten worse, but I'm sure it's been affected by COVID.