We received a wonderful welcome by Maria Pia. She is a wonderful person and caters to her guests very well, living but a few minutes away and ensuring wonderful service despite the place being self-catering.
This place is quite unique in Rome, being part of a 6-small house flowered garden complex surrounded by condominiums. The garden complex is charming, situated on a dead end quiet street that you can get to directly (30 meters at most) from Quattro Venti station. The house is small, but very well organized. We were there a couple with teenage son and had more than enough personal space. Maria Pia ensures you have all the necessities (from detergents, toilet paper and shampoo, to coffee and welcome bowl of fresh fruit).
Quattro Venti is a small, quiet, clean train station where 1 euro will get you to San Pietro (vatican) station in 3 minutes, every 10 minutes or so. All trains in that direction stop at S.Pietro.
In the other direction, the trains all stop at Trastevere (1 stop), where you can take the 3 tram to Circus Maximus, Colosseum, etc..
About a 10 minute walk away is the 8 tram that takes you downtown to Pza. Venezia (terminus) through Trastevere's main street - the first stop is also Trastevere station.
A short walk in the area can also take you uphill to the Gianicolo or to Villa Pamphili, or to take stairs down to Trastevere.
The pizzeria at the Quattro Venti station (right in front of the house) is inexpensive and good value for money. A more expensive choice, but which was absolutely delicious was Osteria Mangiafuoco on Via Alessandro Poerio, a short walk away.
In summary, the house is very nice, clean, with modern amenities (washer, AC, wifi, TV) and a small private terrasse/garden where we ate when not out. Maria Pia is a wonderful, giving host. The location is lovely and well connected by public transport.