This location really is "the best location". It's a few steps away from Ponte Vecchio and within walking distance to the bus/train terminal yet not in the middle of the crowds by the Duomo. Very close to all of the main sites, Uffizi is just up the street. Many charming unique artisan shops and excellent restaurants are just outside. We did not rent a car while in Florence and we never needed one, this location allows you to walk everywhere and train/bus station is about a 15 minute walk. Quiet in the evenings yet lively, about a block away in the Santo Spirito square you can enjoy public markets on weekends and excellent restaurants/wine.
Wifi was excellent, if you have more than four devices let your hostess know and she can give you alternate networks, we found the Wifi to be excellent in this flat. Sibilla answered all of our questions immediately and we found the communication was exceptional during our two month stay. Clementina was there to greet us at check-in and was very helpful.
This flat is best for two people, the couch is comfortable but not really ideal to be used as a bed. The stairs are very steep (and there is no elevator) so while we needed the exercise after all of the wine and pasta and didn't mind them, I imagine they may be very difficult for someone elderly or handicapped. The pictures of the apartment are very accurate, it was just as pictured. Some of the other reviews on here mention neighbors yelling at each other, we did experience this but if you ask them to be quiet, they stop yelling for a few days ;-) Overall we enjoyed our stay and would stay here again, priced very well for an entire private flat.