1.) Noise (Very noisy turbojets with afterburners for takeoff), banned from many airports at night for noise abatement reasons.
2.) Takeoff Run:
Concorde: 11,800ft at MTOW, SL, and ISA.
A320: 6,900ft at MTOW, SL, and ISA.
3.) Fuel Consumption (Longer route: lower impact from takeoff fuel consumption):
Concorde: 46.85lb/mi (standard mile) on Max Range (3900nmi (nautical mile ~=1.15 standard mile)) with 100 seats.
A320: 10.3lb/mi on 2151nmi with 150 seats.
Concorde: 2 Pilots + Flight Engineer.
A320: 2 Pilots.
Concorde: 100 (All Economy High Density).
A320: 150 (2 Class), 180 (All Economy), 189 (All Economy High Density).
6.) Fuel Carriage: LOADS (It uses it to trim the aircraft because of the lack of a movable tail).
Concorde: Old-fashioned trial and error.
A320: Computer-aided troubleshooting.
8.) Supersonic: Only allowed over open ocean due to sonic boom concerns.
Concorde: Analogue, outdated, lacks modern navigation technology.
A320: Cutting-edge short-range computerised cockpit technologies.
10.) Range (Low in regional airliners to keep weight down):
I know the A320 isn't regional either but, for the benefits of the range similarity and the large amount of available data, I chose to use it for comparison purposes.