This apartment is beautiful and is a perfect location in Florence. It is about a 25 minute walk from the train station (Firenze Santa Maria Novella) or a 10 minute taxi cab ride (without traffic; however, note there is usually traffic during the day in city center of Florence so expect a 20 minute cab drive). It is walking distance to the many tourist "to-see's" including Il Duomo Firenze, Academia Gallerie (where Michelangelo's David is located), Uffizi art museum, Piazzas (del Duomo, della Signoria), Ponte Vecchio, Boboli gardens, etc.. The walk to Mercato Centrale is a bit further, but still quite pleasant. It is also very close to some great restaurants (tuscan food) and food options (sandwich shop, gelateria) and a currency exchange shop (called Change Exchange which gives great rates relative to airports and banks).
We met Federico (a friend of Oliver and Elena's) at the front door at the agreed upon time. He was extremely friendly and helpful. There are a couple flight of stairs to go up, but this is not a problem at all. Federico helped us with our bags. There is a gate before the main door which is reassuring for those concerned about security.
The apartment is quite spacious and decorated very nicely. The photos they've captured are representative of the space. They have maps for you to use and Federico was very kind to give tips on some of the best local restaurants. If you choose to use amenities, they have a very nice kitchen, dish washer, and washer for clothes (no dryers in Italy, only clotheslines). The heating/cooling was never an issue. Their place is very clean. The only small note of concern was the smell of odor in the bedroom. It was persistent and smelled like sewage/plumbing from outside (or above?). Aside from this small blemish, everything else was very clean.
Overall, it was a wonderful experience to be right in the center of the city and within 20 minutes walking distance to both of Florence's train stations.