When we arrived at the apartment, which was really straightforward to find, Corrado met us, showed us around and gave very helpful notes on the house, plus advice on nearby amenities and some business cards for good local establishments. The apartment is comfortable, spacious and brightly, warmly furnished, with an excellent little kitchen featuring all the essentials but also extras like a juicer. The bed was comfortable, the bathroom tidy - the hot water doesn't last very long, but it heats up again very quickly. The WiFi was totally reliable. The real bonus for us however was the air conditioning - very efficient and an absolute relief in the hot Roman summer. There are also large windows for a warmer breeze.
The area was close to the Colosseum and Roman Forum but a little way out of the majority of the historical centre (1/2 hour or so walk to reach the central area, longer to go further in), which had pros and cons: it wasn't practical to come and go much so we tended to go out for the whole day (rather than, say, returning for lunch) but it was also lovely to be situated a little away from the touristic centre and crowds and was fairly quiet at night. It was quite a multicultural area with lots of little stores, some nice restaurants and to our great enjoyment (thanks to Corrado and Maurizio's advice) a large indoor farmers market in the mornings, full of fresh fruit and vegetables, meat and fish, cheeses, breads etc which we highly recommend. The apartment is an easy walk to the main train station Roma Termini, but also very close (about a block) to a Metro station which was useful connecting to the Vatican and various parts of the city centre.
Our hosts were easy to contact and offered various helpful options for checkout: leaving the keys on the table when we went was a very simple solution. All in all an excellent stay in a welcoming apartment with friendly, helpful hosts - thanks Corrado & Maurizio!