All in all this is a beautiful apartment within walking distance of all the best sightseeing stuff in Florence. Great value for your money - would book again in a heartbeat.
The room: One large room with one 2-person bed, small table, some cupboards, etc. Suitable for 2 people without kids. Beautiful bathroom and a small kitchen with stove etc although we didn't use it. The ceiling is really high (my guess is 4.5 meters) which is really beautiful.
Location: extremely in the center, everything you want to do in the old city centre of Florence is within walking distance (5-10 min). Really really good location.
One negative: I kind of expected it to be someone's apartment so I expected some kind of authentic intimacy of sleeping in someone's house (first time AirBnB for me) but it felt more like a hotel. Not that this is bad necessarily but I'm just putting it out there.
Bonus: directly next to the front door there is a little place called I' Covo De' Ghiotti which has really good sandiwches for 5 euros.