Location is very central -- e.g., short walk across the bridge to Trastevere neighborhood (and a pharmacy that does Covid testing for U.S. travelers), a Carrefour and restaurants around the corner or immediately downstairs, 20-30 minute walk to Piazza de Spagna / Trevi Fountain or Colosseum. A good # of units in the building seemed to be commercialized for Airbnb or vacation stays. Really appreciated that the place has a small kitchen and washer (no detergent provided, though I bought and left a bottle). Bathroom was very clean, but wished the couch, cloth chairs, and bed linens got a little more attention. FYI, the windows are pretty high up and provide sufficient natural light, but their lower halves are obstructed and don't let light in. I didn't think it was an issue, and there are plenty of lights in the unit.
Rosa was generally pretty responsive and also offered a driver for pick-up at FCO airport, which was nice (and seemed to be cheaper than an Uber or Free Now).
Check-in itself was a bit frustrating. The # provided is for a business, which was closed by the time I arrived around 8:00 pm. I was never able to connect with Rosa by phone or over message during check-in (radio silent, in fact). The driver didn't speak English and did not seem to know exactly how check-in worked. After about 30 minutes, I received a call from someone named Frederico who said he was en route and thought I wasn't arriving until 9:00 pm. He finally showed up and handed me the keys and told me the WiFi password (which otherwise was not provided).
There's a luggage storage place around the corner that I did use to watch my bags for an afternoon, which was convenient. Seemed like it was all part of the same business.