This is a really cool apartment. It seems to be carved out of a courtyard in the middle of a block of tall apartments, which means it is very quiet and separated from the noise of the neighborhood. The Trastevere location is very cool, with lots of activity, restaurants and cafes, easy access to public transportation, and within walking distance of a lot of tourist destinations, including beautiful and historic churches. While the building seems very old, the interior is very modern and spacious. There is a cool rooftop patio, which is a nice place to have a morning cappuccino, or to relax after a day of walking around the city.
There were some annoyances, including a sliding bathroom door that wouldn't open if you closed it all the way (trapping you in), a toilet seat that was broken, overflowing trash bins in the courtyard, and espresso capsules that were the wrong kind for the type of coffee machine that was in the flat. The host didn't arrange for these to be fixed during our five-night stay, despite being notified on the first day, but he did make up for the issues by paying for our cab to the airport, which we appreciated very much. All in all, it was much better than staying in a hotel, and we would recommend it.