We stayed for five days in Cosimo's appartment, and had a great experience. The appartment is marvelous, the rooftop terrace has fabulous views over Florence, just besides the dome of Santo Spirito.
Everything was perfect, better than what we expected by the photos and descriptions!
Location couldn't be better, just 5 min walking from Ponte Vecchio, and plenty of good restaurants and cafes around.

Definitely I recommend Cosimo's appartment!