Some info that I have managed to obtain about revisions I hope is useful:
Launch cars were 2002/02 and criticised for very jerky gear changes, not great handling and some build quality issues. The model was revised with the first 12 months (which says something about how bad the very early cars were !)
Revised cars were 2003/03 reg onward (although there is sometimes some overlap.)
These were much improved. Better software for the Cambiocorsa system (noticeably smoother.) Better software setting for the Skyhook suspension, thicker anti-roll bars, better traction / stability (MSP on revised cars, ASR on pre-revised cars.)
Essentially, ASR is traction control only. It reduces power to the wheel that sense slip. Revised cars have MSP, which includes ASR traction control, but also includes stability control. All in all, a better system.
There were then improvements in build quality, even down to fitted thicker carpets !
Revised cars also has a new colour option (Argento Luna) and the prettier 7-spoke alloy wheel option.
These are definitely the car to go for, unless you can stretch to a facelift model, launched in July 2004 (known as a 2005 model year or 'facelift' car.)
These really are the most sought after and only 89 facelift Cambiocorsas were sold in the UK.
This site I am sure has been mentioned before but I found was very useful:
https://checkvist.com/checklists/39832?simple=true