Costanza's appartment is located at a central area of Florence, within a walking distance to most Florence attractions. However, the bus stop is just a few metres away and you may go wherever you go around Florence.
As for Costanza, she was polite and very informative. The place itself was clean, with all necessary amenities and a very good heating, as we visited Florence at December.
There are two drawbacks to the place, its very low wifi signal, which was annoying and the small bathroom, perhaps some bulky people may have a problem.