Check-in was a mess. I was asked what time I wanted to check in and when I didn't respond quickly (I was travelling) I was asked more and more aggressively and told that I needed to come at their default time of 3pm, and that I needed to give ten a call despite not having a phone that worked in Italy. I understand that they need to coordinate scheduling but it felt imposing and unfriendly.
In person, the service was surprisingly nice and helpful. The person checking me in have me tips on what to see and how to get to it.
The beds are comfortable and the rooms are well-equipped. The Wi-Fi is quite fast.
I didn't notice much in terms of the eco features. No recycling bin in the room but perhaps they sort it out later. The air conditioner has a tendency to run very aggressively, and air conditioners release harmful pollutants, so consider setting it on level 1 or 2 rather than the full-blast of 4, and turning it off when you leave the room. It works quickly so you won't need to keep it on for long.
Two major problems. One, the walls are paper-thin. I could hear every sound from some other guests who were using the common kitchen, in ear-splitting detail. Seriously, someone would drop a fork and it would sound like glass shattering. Try having the other guests shut the kitchen door to block out some sound.
Second, the neighborhood is incredibly run-down. Very dirty, most shops are shuttered, and the people do not seem particularly friendly. North of the B and B towards Trastevere is fine but south and west feel sketchy. Roman public transit is also very very lacking - the buses and metro aren't quite to anywhere, so you'd honestly be better off walking to places. It's often faster. Given the location I can't recommend this place for tourists who want to see the major sites, which are all 30+ minutes away.