We stayed at Carlotta's place in Florence, and we were extremely impressed with Carlotta's hospitality from afar. She wasn't in town, but she made sure we had all the information we needed, and we were able to check in and check out as late as possible because of Carlotta.
Best shower we had in Italy, and the space is larger than you would expect! It's located in a perfect location between the train station and many points of Florence interest.
The only thing to keep in mind, is that there are a lot of stairs, so be ready for that, travel light!