We had a great stay at Mattia's place, for two weeks in February. The first week was very cold outside but the apartment has underfloor heating and a hot shower so it was not a problem. It was so easy to walk into central Florence, around 15 mins, but we didn't always need to as there were so many great restaurants and bars in the neighbourhood.
The wifi is fast and reaches the whole apartment, if you need to catch up on work. Because the windows are north facing it could feel a little dark during the day, and it was too cold to make use of the terrace, but if you come later in the year that won't be a problem. Mattia's agent was very helpful, she even called us a taxi to the airport on the last day. And she has a list of restaurant recommendations, so we had no shortage of places to try. One warning is that even in February, all the good places to eat get booked up so try and plan ahead.