We just spent a few weeks in Florence. It was, single handledly, the BEST I have ever been treated as a tourist/visitor. The nicest people ever.
We did Florence also on this trip and we will be going back for sure!
We loved the city and the people, as you said, were fantastic to be with and deal with.
We went to the Mercado Centralle, as an example. Just about every vendor was very proud of his wares and willing to pose for pics, chat, whatever. We left so impressed.
IMHO the best city in Europe to visit is Krakow. Had a great time there.