My friend and I enjoyed 4 nights at this apartment. We loved being so close to the Duomo, waking up to it's bells in the morning was wonderful. The central location is great - it seemed like everything was 8 minutes away when we mapped it on Google maps.
Definitely bring ear plugs. This apartment is in the heart of the tourist zone so there is noise throughout the night, buskers playing directly under the windows, street sweepers early in the morning. This didn't put me off because I knew what we were choosing.
I would recommend this to couples or friends who want to be in the middle of it all and are prepared to be woken up by noise. Definitely do not recommend to people sensitive to noise or who have young children that are easily woken up.