The apartment is large and could comfortably fit 5 people. The kitchen is well equipped. We didn't spend much time in the apartment - mainly we toured. The location is fine, it's just not really a walking distance from the Colosseum on a hot day, we took buses which run very frequently from right at the corner of the street.
The elevator of the building is very old fashioned, and getting up and down was quite a hassle, especially with a baby's stroller which needed to be folded since the door was too narrow.
Fredricka was efficient and helpful. The AC didn't work when we were there, she immediately sent over a technician who placed a temporary air conditioning to use until the normal one was repaired.
The apartment is on the fourth floor and the windows have no bars on them. Something to consider if traveling with kids.