The apartment is operated by a tourist company, which increased the level of professionalism significantly, but also diminished the charm of Airbnb a tiny bit. Apart from that, the location was beyond optimal. You can literally roll out of bed and be inside the Duomo within 5 minutes! (Given there is no queue, which there always is). Special point to mention was that the company was able to store our luggage even after checkout, since our train ride out of town was in the afternoon. All in all, a very good experience.