Although with a bit of thought on suitable runways you can make both savings by landing flap 3 and using low autobrake or rolling long. Each landing is different, sometimes flap 3 is more suitable, sometimes flap full. Airbus green ops in the FCOM states it’s more efficient to use flap full if medium autobrake is required to vacate at the desired turnoff.
Personally I average about 50/50.
LD