We stayed at Micaela and Davide's really charming Opera studio on our recent trip to Rome and they were very accommodating with our late check-in time. They also gave us local recommendations, which we really appreciated. The AC is a great plus of this listing for the really hot days/nights. It helps during the night to have windows closed as the main street can be a bit busy with traffic/noise.
Like some other reviews mention, the mattress of the sofa-bed could be a little better but it is fine for shorter stays. The shower is okay: we'd ran out of hot water sometimes and the pressure could be better and we found the shower gel sachets to be impractical.
The location is ideal for those planning to travel by train to other parts of the country, but not so much for those hoping to walk by foot to the main parts of the city during hot summer days. There's lots of transportation links, which is good, but there will be a bit of traffic / extra travel time as well.
The kitchen isn't that practical, but you'll likely not need to cook at all when in Rome anyway :) The furniture is adaptable, things fold in/out but it would be nice to have a bit more space to sit down and relax after walking and not needing to fold in/out the sofa-bed every day!
We would definitely recommend for those on short stays and someone looking to stay next to the train station!