We stayed for two nights in wonderful Firenze but our experience with this hostess could have been better:
We booked apartment 313 but when we arrived we met Cristina who told us there was a problem with our apartment and we are moving to a better one. We agreed but it wasn't done cleaned yet so we went out and told to come back after an hour.
When we came back we saw our luggage was move to a different apartment. Cristina came and told us that they made a mistake and we need to move again. This third apartment wasn't as nice as the previous one and when we asked to see the apartment we booked to make sure we got a decent replacement Cristina told us it's impossible because she doesn't have the key. Moreover, this apartment was again not clean and ready yet so we had to go out and wait for it to be cleaned. Total delay in check in was 2 hours after the official time.

We asked for compensation and agreed on late check out.
When we came back we found out there was only one bath towel in the apartment and it was moist. We wrote an email message to Monica but never got a reply.
Other than the bad service the apartment was pretty good for our needs - great location, nice building. The hot water didn't run well and we wrote about that too and never got a reply, to this day.

To summarize - the apartment has many advantages, mainly the location, but the service and communication with Monica and Cristina was bad and not what we expect. We would not recommend this place as a first choice.