The penthouse apartment was a sight to be seen - located right in the Piazza Santo Spirito, we had a beautiful view of the plaza and our side of Florence. To our right, we had a view of the Duomo itself. The balcony was huge and there was a door to the living room as well as the bedroom - you could wake up and walk out to see the sunrise. Truly magnificent views.
The apartment has brand new furnishings, a large bathroom, large balcony, and a large bedroom. The bed was really comfy and the apartment itself was very clean and well-maintained.
That said, before booking this just keep in mind that it is a penthouse and in most of Europe you don't have elevators - it is a bit of a hike up 5 floors' worth of stairs! Also, being right in the piazza, the locals sometimes party and it can be loud. The great side of it is that you are higher up and can see so much of Florence, and there are a lot of locals in the piazza - our last night they were celebrating and dancing to music. Our stay was very special and we would definitely stay in the penthouse again.