Piera is extensively familiar with the city and its surroundings and it shows, and is able to assist guests in find their way around and to the spots they plan to visit.
After hearing about my specific interests regarding the city she lent me plenty of brochures with information about the places I wanted to visit.
She was very helpful at all times. There is a fully equipped kitchen that you can make use of. Piera is around sometimes, never being intrusive but always willing to help, to the point of cutting her personal phonecalls right there to respond to the host (even when I was expecting to wait until she finished her call).
On one ocasion she helped me with the laundry and went completely above and beyond, giving me my clothes back clean and dry, and had them ironed (which admittedly I wouldn't have done for myself away from home and on vacation). At check in time the taxi driver could not find the address and essentially I dropped off five blocks away (I couldn't communicate with him any better). After figuring out where I was, I started walking towards the apartment, and Piera came to meet me on my way there.
All in all, she is a very proactively helpful person that will make sure you can make full use of your time in Rome.
The room is large enough so that a long stay is completely comfortable and it has its own separate bathroom.
Location is excellent. Two or three blocks away from Piazza Navona. It is also within walking distance to the Colosseum area, and I also walked my way to the Vatican and Castel Sant'Angelo area. From the Colosseum you would be two metro stops off from Termini Station. There are numerous restaurants in the area, as well as a number of supermarkets, and a phone shop where you can get a local SIM card, so your logistics will be greatly simplified. I strongly recommend this place.