I loved my stay at Christina's place!She's so immediately warm, welcoming and caring to guests - It's honestly like staying with family. Christina is a very interesting character and I loved having a chat at the end of my busy days. The room is good, just what one needs for a stay in Florence. Bathroom to yourself and a pretty view over the city. The area is great - plenty of cool bars and small restaurants in the area, as well as easy walking distance to all the sights, as well as the bus and train station (very handy for day trips into Tuscany).
Only downsides are the noise from the market in the early morning (price you pay for such a good location) and the room can get pretty stuffy overnight in the July heat but the fan helps that.
Definitely stay again when I come back to Florence.