Sergio definitely has a nice place. It's just like you see in the pictures: tidy, fresh, and comfortable. The breakfast was provided, but we were able to prepare it at our leisure, which was nice for a holiday. Sergio gave us a lot of information upfront about city details and good things to see/eat.
A few things: we were in Rome for a long weekend, and unfortunately that weekend the tram was only part-route (until the last day). It was OK because there was a bus running, but it definitely delayed our journey. On the Saturday it took us nearly an hour to commute to Vatican City. I imagine on a normal week this isn't a problem, but it's definitely something to consider if you have only a little time. You're dependent on public transport at Sergio's.
On the plus side, being a bit outside of the city has its perks. We ate dinner twice in Sergio's neighbourhood, and both times had delicious food at nearly half the price of the restaurants in the city centre. Also, it's much more local, so you get a vibe of the city without the tourists.
So, a few things to consider before making your choice, but I definitely recommend Sergio. He's a great host and you'll be comfortable during your stay in Roma. Thanks Sergio!!