Katia's place is all about location. My boyfriend and I easily walked there from the train station, and could find everything we needed within a decent walking distance. It is truly a block away from the Cattedrale di Santa Maria del Fiore, and a short 10 min walk from the Palazzo Vecchio, the Uffizi Gallery, the bridges, etc. It worked perfectly for us because we were in the city for only two days. The drive to the airport was barely 20 minutes.
The airbnb is in a secure building, they have elevators, and it is a spacious apartment. The bed is very comfortable, the view of the Duomo is even better than the one showed in the photos. I read in past comments that the shower didn't have a door; this is fixed. We arrived and the bathroom was completely fine.
We would only like to note that while there was hot water, it only ran for about 12 minutes, and after that we had to wait a long time for more water to heat up (over 5 hours). The thermostat also seemed to be broken because the place wouldn't heat up, but I trust they will get this fixed.
Other than that, we had a good stay at Katia's place!