If you were planning to spend two or three nights in either Arles or Saint-Rémy, which would you choose? Arles for two nights with maybe a day trip to Saint-Rémy (you have access to a car), or Saint-Rémy with a day trip (or maybe two) to Arles?
To expand on personal taste and travel style: you're not a big fan of heavy tourist areas, but you're a history nut. You love to walk down to a locals-only cafe for the best meal of your life, and stroll around charming streets, discovering little (non-tourist-trap) shops. You do love open air markets, and especially when they're crowded with more locals than tourists.
Did that make any sense? Just trying to gather some opinions for my parents, who have never been to Arles or Saint-Rémy. I have been to Arles, but not Saint-Rémy, so I can't speak knowledgeably on whether one trumps the other based on what I know they like to do.