As a starting point, but not a full definitive list:
Arriel 2s2 engines (about 6% more power)
Inlet Barrier Filter
Full FADEC on engines
No more Mixed Mode on the throttles
IIDS software upgrade
Light weight inverters.. Check you have the AC generator still wired into the AC system. Seems a bright spark decided that the feature wasn't needed after 25 years and it was removed. No one told the test pilots though
It is being reintroduced after S/N 640.
No direct mechanical link from the throttle to the FCU. now via dual DECU's
Can now do power assurance check in the air, and not only on the ground.
hope that's a good starter..