The claim to fame of this hotel is based on the fact that 15-year old Mozart stayed there for 2 weeks with his father in 1771.
Nothing changed much there since (except for plumbing, of course). 3 rooms on each floor facing the street were obviously intended for the important guests and still are furnished accordingly, while other rooms facing inner yard were for the servants, coachmen, maids etc.
Hotel serves only standard breakfast in the magnificent ballroom under subdued soundtrack of, or course, Mozart, but there are unlimited number of very good restaurants within 5 min walking distance, including 3 in the same block as the hotel.
Location is also very good - 10 min walk to Piazza Castello, the tourist center of Turin, and 20 min walk (or 10 min on a tram 4 or 11) from the train station. Hotel also has a small parking, but reserve it asap)
One strange thing was that under pretext of Italian Law we weren't allowed to bring glass glasses from the breakfast room to our room (I plead the 5th amendment for the rest...)