I know this is like comparing apples to oranges, but if you had four days to spend in either Arles/Avignon OR Nice/Cannes/and maybe Monaco which would you chose and why?

Arles/Avignon/Nimes would be my choice, wide range of buildings from Roman times forward, little markets, popes palace, lovely little restaurants, fine vistas and easy public transport etc etc

I have no interest in Casinos (father gave me "make him gamble as a kid until he is sick" medication), I grew up amongst luxury yachts (so bored by them) and so see no reason to visit Nice/Cannes/and maybe Monaco. I have no interest in visiting Vegas either

Arles/Avignon is Provence, Nice/Cannes is the Riviera.

The ambience is very different, you must decide which you prefer. The season of your visit is also a factor, as the Rhone valley can get very cold in winter while Nice is pleasant most of the time.

Thanks! That is the kind of clear and helpful response that we needed to help us decide on Arles/Avignon.

Arles/Avignon would be my preference, but I have little tolerance for glitz and celebrities.

Arles/Avignon are true Provence.
Monaco, cannes are ostentation kudzu.

Nice I like

BTW, Nice and Cannes are in Provence, too. The Riviera isn't a province.

Those are my own definitions, stcirq, not stated as geographical facts.