I've only got Buenos Aires to compare it to but somehow Rosario felt a lot more Argentinean, less cosmopolitan, with fewer tourists and just people getting on with their lives. I was introduced to Folklore in Rosario, a type of music that is a lot more common all over Argentina although maybe not as famous as tango, which I'm told is more associated with BA. Fran, some of her friends and I went to a restaurant/bar/café for some empanadas (dulce carne and quesa y cebolla, my favourites that I've tried so far), and to watch Jose Simon, who was pretty amazing.
The next day I had a bit of a lie-in and then we went back down to the riverfront and wandered down to a restuarant where we had the most amazing river fish with patatas fritas, and then had a look round the markets and went to a contemporary art museum. Later we took advantage of the ice-cream store near to Fran's apartment and had a relaxing evening in.