This is a spacious and charming two-bedroom unit on the top floor of an apartment building, with beautiful views of the neighborhood. Although it's tiny by American standards, an elevator provides access to the floor -- you don't want to carry your luggage up five flights of stairs!
The apartment has both dish and clothes washers, and wet clothes may be hung outside on the balcony to dry (you may need to buy clothes pins). The kitchen is well stocked with pots, pans, plates, cups, glasses, and utensils, and at least three markets are located within a few blocks.
If you don't wish to cook, the neighborhood offers many excellent restaurants for dinner and abundant patisseries for morning espresso or cappuccino. Prices were very reasonable, as the neighborhood is not a major tourist site (like Piazza Navona).
The apartment is a 15-20 minute walk from the Termini rail station. A bus line runs on an adjacent street, a second bus line is a 5-10 minute walk, a Metro stop a 10-15 minute walk, so getting to the apartment from the main train station and to the tourist sights of Rome is straightforward once you get your bearings.
You may find the San Lorenzo neighborhood disconcerting, with graffiti on the walls and litter in the streets. I'm a 60+ white male and felt safe; however, my 25-year-old daughter didn't feel comfortable walking alone, particularly after dark. The streets seem well populated throughout the day, so if you remain on the main streets, you'll find people around you.
Returning to Rome, I wouldn't hesitate to stay here again. I think the neighborhood has many hidden gems that reflect the local culture, including a pasta store on the same street. If you want to avoid the tourist crowds, yet have easy access to the major sights, this is a great home base.