Superb location. We didn't know that Tournabuoni is a high end shopping hub, the flat squeezed between Tiffany&Co and Armani. While it's a bit out of my price range, if you love high end fashions like Gucci, Prada and Farragamo, this is the perfect location for you.
Also very close to all the attractions on both sides of the river. The apartment was very clean. Has a small kitchenette (which we isn't use). There's also a sleeper sofa in the living room (also didn't need).
The only con was that there were a lot of stairs to climb so be aware of that if you bring a lot of luggage for your stay. It can be a hassle at the end of a long day of walking :)
All in all, an amazing place in an amazing city.