The apartment is large, stylish, well-equipped and in an excellent location. We had a party of 4, but the space can easily accommodate 6. The view from the front terrace over the river Arno is awesome, most of the important Florentian historical landmarks, museums and attractions are within walking distance or a short bus or cab ride.
Our host was extremely helpful, responded promptly to questions and provided me on top of that with valuable information regarding Tuscan locations and properties. There are detailed printed explanations in the apartment how to get to the attractions. There are also very informative books and of course a fast WiFi connection is conveniently available. Important for (us) Americans, the A/C units are efficient and low-noise (Mini-Split units). Beds were very comfortable and we all slept very well. The parking (garage in the basement underneath the house) was a very much appreciated additional value as parking space in Florence is very hard to come by.
It has been mentioned in a couple reviews that there is traffic noise coming from the main road at the front-side of the apartment (toward the river). While this is true, it should be considered that Florence is a very busy city almost year round and that the location of the apartment is so prominent and convenient that the traffic comes as no surprise. In this connection it should be mentioned that the apartment is extremely well noise-insulated. You do not hear the traffic in the bedrooms (which are located toward the backside of the apartment) at all, and even in the common living area and kitchen (situated at the front of the apartment toward the main road), the noise is minimal if the door to the terrace is closed. If you enjoy sitting on the terrace in the pleasantly warm evenings, the noises of the city become soon a distant background and they also quiet down a lot in the later evening hours. We sat on the terrace almost every evening for at least a couple hours during our stay and we very much enjoyed how lively Florence is in general.
Tl;dr: Perfect apartment, perfect host, perfect stay, would love to stay there again.