We spent one month in the apartment ! It's very quiet ... except during our stay as the church facing the living room was under renovation :( It was a bad news for us as we work at home and we specifically asked if there were any noises and the answer was no ....
Otherwise the apartment is quite confortable, very light, with a clear view from the living room, the bedrooms are facing a small indoor courtyard.The kitchen is small but well equiped. The location is really good, 10 min walk from the Cathedral.
Cons : the hot water tank is really really small so you can't take a long shower and the next person have to wait 20 min to take a new one ... not practical ! Also the insulation is quite bad so in winter it's chilly even with the heater !