I would highly recommend Francesca’s place! It was in a great location, very close to the Duomo and a decently short walk to pretty much anywhere you might want to go in Florence. Francesca was also very responsive and provided great instructions during our stay.
The only downside was it was very hot in Florence during our stay, and A/C is not allowed at night. The apartment is also on the first floor, so street noise is very loud with the windows open. This made it very hot at night and difficult to sleep. However, there was a fan in the bedroom which helped a little!