Niccolo's place is pretty much as described, on a busy street in Florence about half a kilometer from the train station. At least it felt that far with heavy bags in the later part of a tiring day. We never met or spoke to Niccolo during the entire stay but his friend was around to receive us at the station and to check us in. She was also pretty responsive over SMS when I needed some help on the evening of checking in.
All the amenities were available as promised.
The apartment was sufficiently spacious for our family of three and clean.
We did have issues with the air conditioner and could not easily get it to work. The remote was highly non-intuitive and we found the apartment getting fairly warm in the night.
We also found the washing machine difficult to use as all the text was in Italian and for some reason it would not complete the cycle by itself. Even after two attempts I could not get it right.
Please ask the host at check-in time about about how to use them both.
The mini-kitchen is nicely concealed behind doors and it was a bit inconvenient to open it every time to use it, but that is a minor point as we did not really use it that much.
There are a lot of restaurants and grocery stores in the immediate vicinity of the apartment, so that was very convenient for us to get dinner and breakfast.