This apartment is great. This was our first trip to Italy and when we first arrived we weren't sure what to expect. The taxi dropped us off on a small street and we waited 5 or so minutes for Erika to arrive. Once settling in however we couldn't be happier with the location and setup of the apartment.
As others have mentioned, there are several stairs, but that was really only an issue the first and last day when carrying luggage.
Erika was great in providing us tips on where to eat, arranging a taxi for us to the train station and even attempting to reserve dinner for us. Other than the train station we walked everywhere as the apartment very close to the Duomo and museums.
The apartment is also very spacious. We left Florence for Rome and were disappointed at how much smaller our apartment in Rome was compared to Florence.
Overall we would definitely recommend this apartment.