From this topic on a prior forum post: https://community.ricksteves.com/travel-forum/france/avignon-or-arles-c897c949-1ff0-4cca-8e26-dfca4bb2bf7c this was my entry:
"We stayed 4 nights in Arles in May. We rented a car 2 days to travel to St. Remy, Les Baux-de-Provence, Pont du Gard, and Saintes-Maries-de-la-Mer. From SMdlM, we walked along the shore trail and viewed lots of wildlife (including flamingos).
I preferred visiting Camargue National Nature Reserve on a bicycle from Arles along the Petite Rhône, where we passed the farms of the famous cows and horses. On a bicycle we were higher than auto passengers and could see the flamingos on the other side of the dike that they couldn't see.
We preferred Arles, because it was more of a town feel. We loved being in the town where van Gogh paintings were staged at the spot they were painted. We found our favorite bakery for breakfast and good restaurants for dinner. You sound like you have more train travel to other sites, so Avignon may suit your needs better. It was a 20-minute train ride between the 2. We spent an overnight in Avignon, so we could take the TVG to Paris in the morning. Avignon definitely has better train connections.
Our hotelier had the bicycles and recommended the car rental business. In 2011, some things were not booked in advance. Saturday was the local market day. We loved wine shopping in the caves of Les Baux."
