This is a genuinely nice and quiet area with a couple of great restaurants within a two minute walk of your building. The location has decent parking - although you may have to hunt for a few blocks, we did - and is about a 15 minute walk to the Colosseum. At the Colosseum, there are taxis everywhere, so you can travel wherever you like in the rest of the city.
The apartment will comfortably fit four people, so long as people do not mind sharing, although there is a small couch you could probably squeeze a fifth person on to. But I would recommend no more than three as it is a relatively small apartment and more than three and you'd probablybe stepping all over each other.
The modernized fixtures, air conditioning and the fact that there is a small elevator were significant pluses for our stay. I believe most small groups would be very satisfied staying here.