The flat has a nice central location, very near to the San Lorenzo Market and a lot of local trattorias to eat in too! Also near the Santa Maria Novella Station and walking distance to the Duomo which makes it all the more convenient.
We were a bit worried about the area at the start but let me assure you that the area is very safe--safe enough for 2 girls traveling all over Europe!
Tommaso is such a gracious host, exceptionally friendly and very accommodating. He even has a map of Florence in his place and could teach you how to get to certain parts of Florence. The flat is very clean, comfortable sofa bed. Although the second floor's ceiling is a bit low, we did not feel it was such a huge hassle.
Perfect flat for Florence, two thumbs up!!