Alberto's place is beautiful and great to stay in. The location is ideal for exploring both the Centro Storico, the Vatican and the Roman landmarks as well as venturing out to Trastevere (obviously) or Testaccio.
The furniture, books and the decoration make this a really nice place to spend time in, the wifi was very fast (sufficient for two people to work from there) and the washing machine and kitchen are useful if you plan on staying longer.
The place is situated on a more quiet street within Trastevere, but it's still within Trastevere, so expect some background noise of people walking & talking in the streets until midnight.