Great little apartment, very clean and nicely decorated. Good shower [let it run a few minutes to get unlimited hot water], good aircon and wifi. The roof terrace is lovely although it only looks out over the street and you can only just see the tip of the duomo!
It's in a convenient spot and Florence is easy to walk round. There's a Pam supermarket 2 mins away and a fresh pasta maker on the other side of the road.
It is, however, noisy. Street noise is expected, there is a bar nearby and people out on the street until late. However, there was also loud music/tv coming from the next door neighbour into the bedroom until after midnight a couple of nights and ear plugs can't block that out.
Note that, as others have said, the stairs are steep and if you have mobility issues or are generally unfit, you might struggle. No icebox in the fridge and no extras such as milk left [but you can request some which you pay for]. The host is very nice and gave us some good restaurant tips [Brac Bookshop/Restaurant is excellent for vegetarians and vegans].