We stayed for a month with two kids under six, and did a mix of going to the beach and exploring Rome and its environs. For our purposes, the apartment was very well located . The kitchen is small but adequately equipped so that we were able to prepare meals for ourselves. There was a superb market a short walk away where we could get fresh seafood and meat, fruit and vegetables, bread, and sandwich fixings.
Giancarlo and his wife are gracious hosts, and live right across the hall so if anything came up during our stay, we were able to get it addressed immediately. Otherwise, they let us be to have our quiet family vacation.
To get into Rome, you take a bus to the train station and transfer. I'd say depending on the timing of the bus and transfer, it takes about 40-45 minutes to get to the Colosseum, and just about an hour to the Vatican. Ostia Antica , which is only a single short bus ride away (or one stop on the train) was very well worth the trip, too.
There is a bar (nightlife) at ground level near the entrance to the complex, and between that and the beautiful piazza across the street, evenings could get a bit lively, but nothing too extreme. The beachfront is a block away, and there are both public and paid beaches within a 5-10 minute walk.
Overall we had a very positive experience!