We had a great time at Margherita's place. It felt very safe behind three locking (and modern) doors - one at the entrance, one at the common place, and one at our private room. Keep in mind that the kitchen is shared, but the bathroom is not so you get both a private bedroom, and a private bathroom, which is great.
Breakfast was provided every day in the form of packaged pastries, rusks, jam, and instant coffee and teabags (a personal electric kettle is provided). There are no breakfast hours so you can eat whenever you choose.
Margherita was very helpful with suggestions on how to get around, where to go (points of interest); she also suggested a couple of great restaurants and a frankly amazing take-out pizzeria that is open until mid-night, if not later.
The location is about a 15-minute walk from Termini Station, which is very convenient for early departing flights - you can be at 5:10 at Ciampino Airport if you catch the 4:30 bus from Termini. If you want to walk to where the main attractions during your stay, you might find it quite tiresome. If you don't mind using public transport, however, the location is very well connected.
Overall, a great place to stay.