This is one of those places that needs six stars. We've been lucky and never had a bad experience with AirBnB, so every place has been lovely. But Donatella's apartment is one that is so extraordinary that it's difficult to find ways to do it justice.
Obviously, the best bit is the view. Piazza della Signoria is one of the world's most beautiful public spaces, and you will get a a front row seat to see the world go by. Having some incredible art out the window is the icing on the cake.
That aside, the apartment is beautifully furnished and laid out, with lots of space and nice touches. The bed is comfortable, too. The location is also ideal, with pretty much every major sight within a 10 minute walk.
Overall, we can't recommend any place higher. Staying here made our second visit to Florence an absolute joy.