Maria's flat is lovely and spacious. We traveled with a party of six and everyone was very comfortable. The three bathrooms was a huge benefit when the party included four ladies. The kitchen was well equipped, though we did little more than make coffee most of the days we were there.
The porch was huge - big enough for a six-person table. It provided a great view of the neighborhood and I enjoyed drinking my espresso out there in the morning and a glass of wine in the evening before we retired.
Everything was clean and well kept.
The flat is located just a few minutes' walk from St. Peter's Square, so you have easy access to the Vatican. It is also just a few minutes from the Metro, which means you are just a few minutes walk & ride from the Colosseum and Forum areas. There are also bus lines that are easy to access from there. You will want to get the bus app to manage that.
Maria and Camilla (Maria's daughter) were very helpful in offering advice about things to see and do. Maria helped us arrange a very reasonably priced van to and from the airport. i considered using the train system, but for the price, it really wasn't worth it. I suggest using that service. It's farther than you would think. Camilla works for a tour company and we booked two tours with her company. The tours were fantastic.
Overall the house was excellent and the support Maria and Camilla provided was excellent. I was impressed with the value.