My mother and I enjoyed a lovely three nights at Maria's apartment. I was amazed at how quiet the apartment was, given that it was right in the city center. The decor was classy, the location unbeatable -- literally steps away from the Piazza della Signoria -- and we felt very safe as two women travelers. Such a nice gesture that fresh fruit was left for us. The large bed was really comfortable, but I would say that the other beds (slightly smaller than American twins) are better for kids -- though for smaller adults they would likely be fine. Maria was highly communicative throughout the process, even when we got stuck in major traffic. Overall, I would recommend this place to anyone!
A note to travelers returning a rental car to Florence: the rental car return is NOT at the airport. Follow the small signs marked "Return Car" towards Via Palagio degli Spini. Try to avoid the evening hours, as we got caught in major traffic, and more traffic after making a wrong turn. Note that the wait for a taxi can be long (we waited almost 45 mins), so leave enough time.