The apartment is in a fantastic location. It is within walking distance of many of the main sites. It was a longer walk to the Colosseum area, but we only went there once, so it worked out fine for us. We felt very safe walking around the area even late at night. The building was very secure and also felt safe.
Keep in mind when you book, that apartments in this area are not luxurious. The buildings are old and quirky. The shower was small and the tub walls were very high which made getting into it awkward. Our showers needed to be short so the second person could have hot water. If you want to stay in this busy area, you will have night time noise in any apartment. The plugs didn't work well, we couldn't get the one in the bathroom to work at all. The walls could use a good scrubbing.
We used the air conditioning, and the washing machine/drying rack. We didn't cook, but we used the refrigerator. The bed seemed to be a queen size bed (American size). The WiFi worked better than we expected from reading the other reviews. There are plenty of restaurants in the area, and a market nearby.