The apartment is great - spacious, comfortable and fully equipped - as advertised. Though located at the heart of the lively Trastevere, it is in a quite street so noise was not an issue (do expect to hear some church bells however :) ).
I had't had the chance to meet with Lorenzo himself, but his assistant who welcomed us at the apartment was very nice and helpful.
Communication with Lorenzo was great - he was professional, courteous and very quick to answer all emails and questions. We had a minor issue with the water hose during our stay and I dropped a line late at night - had an email waiting for me early in the morning and a handyman was immediately scheduled to arrive.