Antonello's place is situated in the best location possible; most major attractions (from Vatican City to the Colosseum) are within walking distance or a 10 minute bus ride (the bus stop itself is about a 1-2 minute walk away). It also neighbors restaurants which is extremely convenient if you are in desperate need of a meal (with luck, I walked into Taverna Lucifero which is a 30 second walk to the left and it was by far the best Italian meal I have had).
Antonello's place can best accommodate at most a couple. I believe it is less than 200 sq feet altogether; not spacious but extremely cozy. The pictures are accurate; bathroom is clean, kitchen is fully equipped, washing machine is included, heater kept the temperature nice and toasty, and the bed is comfortable. Wifi is also included which you can disconnect and use as a hotspot during your travel.
Unfortunately, I never got to meet Antonello but we kept in touch and he checked in through the app WeChat during our stay. Antonello had a friend who welcomed us and was sweet enough to carry our luggage up the stairs.
I highly recommend Antonello's place!