Raffaella's place is in a fantastic location, right in the heart of Florence. It's approximately a 12-15 minute walk from SMN station, and the easiest way to find the apartment (and, indeed, most places in Florence) is to get to the Duomo and navigate your way from there. It's also approximately a 3 minute walk away from the Uffizi, 7 minutes away from Pont Veccio, and 10 minutes away from the Basillica di Santa Croce - so a perfect base from which you can explore the city!
The apartment is very spacious. We were four adults, and had plenty of room; the two bathrooms were also very welcome! There are small grocery shops and supermarkets around the corner from the apartment, as well as plenty of cafés and restaurants, so eating in or out was never a problem.
We were met at the apartment by Raffaella's friend, Eleanora, who was very friendly and helpful. She showed us around the flat, gave us maps of Florence, and gave us restaurant and shopping recommendations. The apartment is owned by Raffaella and her brother Luca, and their office is on the 1st floor of the building (the apartment is on the 2nd floor) so they and Eleanora were generally available to answer questions.
All in all, we had a lovely stay in Florence; it's a gorgeous city, and Rafaella's flat allows you to stay in the hub of activity.