We had a great and long stay in this flat - the flat is larger than it appears in the photos and the location cannot really be beaten. The view from the kitchen and sitting room is over the duomo and onto a palazzo which is beautiful to look at.
As other reviewers have noted, the location does mean that there is some noise in the living spaces but the bedroom is in the back and, duly, is quiet. You will however get to know the musicians in the piazza duomo well, for better and for worse. Otherwise, the flat is appointed to an acceptable standard and the kitchen and bathroom function well. That said, for a long stay it is not sufficiently equipped. The internet does not work well in all parts of the flat which could be a problem if you plan to work from there but otherwise I don't think will be a problem.
Antonio was a great help - always available and understanding. Impeccable service from him.