Chantilly Expo is mostly large open space in 2 buildings - strictly a drive-to venue - surrounded by fast food, as you describe. Now that Metro Rail is open to Dulles airport and beyond the Reston vicinity has potential, but at present there is no building with a large open area plus smaller meeting rooms. It also more drive-to if you want wide hotel selection.
ANA simply doe not have much "creative culture." Management plods along, members plod along (I'm a plodding member, too), and the whole thing just squishes mud.