We had a nice stay in Florence, but there are a couple of things to note:
On the plus side, Carlotta let us arrive early to drop off our bags, and the apartment is large, spacious, and very central.
On the other hand, the cleaning fee was rather expensive but the apartment was not particularly clean (there were ants and some mold/odours in the bathroom), and we did not receive information about the check-in until our arrival in the city.