My husband and I had a fantastic stay at Margherita and Lorenzo's beautiful apartment. The location couldn't be any better, directly opposite the entrance to the Mercato Centrale, a short walk to the Duomo, and lots of other must see sights in Florence. There are lots of great bars and restaurants within minutes of the apartment so you don't need to worry about getting back after dinner.
The apartment itself is modern, comfortable and probably the cleanest place I've ever stayed. It can be quite noisy at night due to the market being right outside and the bars in the evening but Margherita and Lorenzo leave ear plugs for you and it's a small trade off for being in such a great location.