The apartment is fantastic. It has all the facilities you could need, including two bathrooms (one with a bath) and a fully equipped kitchen. Everything was clean, tidy and well thought out. Our host was available by phone throughout our stay and helped us tremendously with any questions.
Location couldn't be better, right around the corner of the Duomo. Perhaps the one downside of this is that there is quite a lot of noise from the street at night. For us, this wasn't a problem, but it's something to consider if you're a light sleeper.