We had a great stay at Simona and Fabio's apartment. It's very cosy and it has all the necessary appliances for a holiday stay.
The apartment is in a nice and safe area of the city. While not in the centre, it has good transport links.
The terrace is huge and it's a shame we couldn't enjoy it (we visited Rome in November) but it's definitely a plus for the summer.
The pizzeria near the flat recommended by Simona and Fabio is definitely worth trying. The starters are delicious and the pizza is amazing!