If you are trying to make an 8 p.m. flight on Delta, it sounds like this would place you in the Centurion Club around 6:00 - 6:30 p.m., which is "rush hour" in that place... I used to hit it pretty often around that time but finally stopped going because it was so crowded-- often standing room only.

IMHO, it's really not worth it over the SkyClub... and that is BEFORE factoring in all the complicated logistics.