120k miles for a belt is an awful lot of miles.
I would look to replace it at half that
I agree and as an Alfa owner it is something I would never hesitate over. However I have a Peugeot as well and that is somewhere in the region of 120k as well.
My brother-in-law had a cambelt fail on his Alfa V6 about 5 years ago. Not sure of the exact bill in the end, but it was well over £2k!
I used to have an old shaped R reg Vectra V6.
VX used to say that the scheduled interval for changing the cambelt was 80k.
However, they started to get a lot of failures at around 50/60k. They of course honoured the warranty, but then changed the recommended interval to 40k, but never really publicised it!