Maura's apartment is located about a ten minute walk from the main Train station in Rome. Your GPS will probably have you enter the street Maura's apartment is on from Cavour Street. Just be aware that if you have any mobility issues, you may want to take a different route as you will have to walk up about three sets of steps. There is a way to get to the apartment though that doesn't require stairs so if mobility is an issue, ask Maura to give you the other direction.
We found the location to be ideal for getting to and from the airport, and to all of the key historic sights in Rome. They are all walkable and if you are fit and energetic you can even walk to Vatican City. Makes the location pretty ideal. There are lots of little local shops, restaurants and a grocery store within 5 minutes walking. The Termini rail station has a really great shopping centre and food court in it as well and is only 10 minutes away.
The apartment is a great size, has great heating and the bed was big and comfy with a nice big feather comforter to keep you warm. There is a very small kitchen (as shown in the photos) that you could use to make simple meals but we mainly ate out. The apartment is really quiet too - no street noise.
The main area we would improve would be to have better block out blinds at the back of the apartment as it is quite light through the night.
It was a great four days stay for us and while we didn't meet Maura in person, she was very friendly and responsive via email.