Andrea's apartment was fantastic. It was within a 15 minute walking distance of all the sites we wanted to see, and within about a 5 minutes walk of major sites like the Duomo and Accademia.
The apartment itself was spacious and clean. The pictures are accurate. While it is in a busy area, it's on a side street, so it's not too noisy. I used the washing machine in the apartment, and it worked well, but you will want to note that it takes about 2 hours for a load.
Andrea was nice enough to meet us at the train station and walk us to the apartment (and he carried my wife's bag). He had a snack and bottled water waiting for us, which was a nice touch.
I would highly recommend Andrea's apartment. Of the 5 places we stayed on our European vacation, it was my favorite and by far the the best value.