We stayed at Emiliano's apartment for a few days. We weren't able to talk to him in person, but he was still very nice on the phone.
We were also able to check in at 21/22 without any problems.
Unfortunately I can't speak highly of the house. The sanitary conditions were really bad, especially in the bathroom where we noticed rotting mold under the sink and on the walls.
Our room did not represent what we had seen in the pictures. Very small and bed difficult to share as two adults. We suspect there were other traces of mold (well hidden by some painting or closet) because we spent the nights coughing.
Also, the theme of the hostel is not very present except for some music themed decor. We asked the host to give us some advice on where to listen to live music and he sent us a list with clubs of which unfortunately 70% no longer existed. It is not a musicians' hostel where between one espresso and another in the kitchen you have a jam session.
Location ok, the neighborhood is young and not too far from downtown.
For 50 euros per night, in low season, in Rome you can find a lot better.