I really cannot rate my experience highly enough. I came to Rome for 6 weeks for work over the summer, and this unit was perfect for my needs.
Host: I have nothing but good things to say about Valentina as a host. She does a very good job keeping the shared spaces clean and in return really just asks that you pick up after yourself and be a conscientious roommate. My trip was complicated halfway through by a medical emergency, and Valentina was extremely helpful and kind while I was recovering. She is also very respectful of her guests' privacy.
Space: I will say the space is on the small side, which was not at all a problem for me but might be a little cramped for multiple guests or travelers who want to have a lot of private space at their lodging. Internet, utilities, and appliances all worked great the entire time I was there. There are also two very sweet cats.
Location: It isn't the most centrally located, but it is right off Line A. I commuted to the vatican library most mornings and it took be about 40 minutes door to door. For some, the location away from the city center might be a bit of a draw back, but I enjoyed being away from the tourists traps in a more residential part of the city. The neighborhood itself has a really nice character, and has everything you could need in the way of grocery stores, greengrocers, pharmacies, caffes, bars, shops, etc. The apartment is also close to parco degli acquedotti, one of the most beautiful in the city (and criminally underrated!).
10/10, I had a great stay, and would definitely stay here again on future trips.