Cecilia's flat was great !
We enjoyed the neighbourhood, the caffe just next to the flat, and how easy it is to walk to the center (20/30 minutes walk)
The bus for the train station is just by the flat too
The flat is great for a couple, it can be "noisy" because the windows aren't really soundproof, and trains passes by (not during the night though, so doesn't trouble the sleep ), but it's still a great place to stay, and not that expensive for Firenze
I highly recommend