My friend and I had a wonderful time at Thalia's beautiful place! The apartment is very clean and equipped with everything you need. There are only little windows on the top of the room but therefor there is a wonderful garden, where we enjoyed breakfast and dinner and felt very italian :) Thalia provided us a map and gave us a lot of very good (non-touristy) advices!
You can reach the heart of the city by foot but be aware that it might take you half an hour after spending the night somewhere in the south of florence. But there are also several busses nearby.
If you want to explore the non-touristy Florence, staying with warmhearted hosts - choose this place!