Staying in Salvatore's apartement was wonderful. It is exactly as described : clean and well equipped (everything you need to cook and wash yourself). It is located in Via dei Tribunali, a lively street with the best pizzerias and many groceries (if you want to eat at home), and calm during the night. You can easily walk to the central station Garibaldi (15 min) or to the Duomo (10 min), or even to Piazza del Plebiscito and the port (30 min). I highly recommend it !
Just a little advice : if you come via the bus from the airport and have a lot of heavy luggages, you should take a taxi from the piazza Garibaldi (the bus stop) to the apartement because of the pavements...