Alexandra's studio, while small, is a great launchpad to visit Florence! The neighborhood is great, with everything you need for a short stay and most touristic spots withing a walking distance. The vintage photo booth around the block is a great way to get a nice souvenir, and the trattoria downstairs is a very good spot for dinner (one might want to pack some earplugs if your stay includes a Saturday night though!).
When it comes to the flat itself, the vintage decor is cute and cozy, though there are two main downsides : as others have pointed out, the mattress of the convertible couch is really uncomfortable, though it is supplemented by several pillows, and the kitchen is extremely tiny, as it was clearly installed in an old closet. This might therefore not be the best place for people who intend to take advantage of Florence's great produce to cook up nice meals!
We still really loved our stay overall, and Alessandra and her husband were very good hosts, especially when they let us drop our bags early on the first day so we could explore the neighborhood freely!