We had a great stay in Florence at Niccolo's place. There are a few things to be aware of, but I highly recommend it.
The location is great, at the rear corner of the Santa Croce church. It is a nice walk to most things in the historic district. It is a pretty far walk from the train station, however. We did it, but we were pretty tired after.
The room was very clean. The owners did a good job of making sure things inside were ready and clean.
A few things to be aware of. These are not intended to be negative, but just things that a visitor needs to know.
The woman that met us did not speak English. She spoke Italian and French. We could communicate a bit, but she would call someone else to talk to me if there was something important.
The air conditioning is tricky to use and easy to mess up. You have to turn on the ACs in order from front to back. They will stop chilling at some point and then you need to reset them. There is a process for that that they will tell you about if the need arises.
Finally, for the ones that stay in the back bedroom, beware of the step of death. As you leave the bedroom, you will see clearly in front of you a step up into the living room. It is marked and easy to see. However, before reaching that step, you will step into a very short and unmarked step down that is virtually invisible. It is usually jarring for the back since it comes when least expected.
I don't want these to detract from am otherwise terrific house. I recommend the house very much.