The pros: Excellent location (right next to the central market, and a few minutes' walk from the train station and historic sites), good sized space, well equipped and well decorated. Carlotta was also flexible in offering us a later check-in time, due to our flight getting in late.
The cons: The heating was very high and couldn't be adjusted, which meant we needed to leave the windows open all night to sleep. Unfortunately the square next to the apartment was noisy until about 2am, and then the garbage trucks came out at 5:30am, so it was very difficult to sleep. We managed for one night, but if we'd been here for several nights I think we would have been zombies by the end of our stay.