Cristina was a lovely host and did an excellent job communicating with us prior to our arrival. She included detailed instructions on how to get from the train station to her home and about check in. Upon arrival we were met by her friend who let us in, showed us around the apartment, and turned over the keys to us.
I think Cristina's listing very accurately describes the home but I will say that I think the glowing 5 star reviews from other travelers got my hopes a bit high for what to expect from the apartment. Ultimately Florence is a medieval city and the buildings are old, including this one.
The biggest positive to the apartment is the location with it being so centrally located on a very nice street. Because of that, Cristina's home is a great value. The air-conditioning and wifi both worked well and were very and were appreciated after long hot days. Cristina left nice touches like toiletries in the bathroom, espresso, and maps/guidebooks for the City. We also appreciated the use of the in-apartment washer.
There were a few things that made the stay less than enjoyable though. Others have mentioned the stairs, which were fine to climb, but very dark when returning at night and we saw a few crawly things which we found unsettling. We also found the bed to be too hard for our liking and the upstairs neighbors weren't intentionally loud but sounds carried very easily through the ceiling; both of those contributed to a couple rough nights.
Overall it is a fantastic value and you can't do better than that price and location. Just be aware that when you rent a medieval apartment there are always caveats!