We stayed at Antonio & Valentina's place for 2 nights. The place is a bit small, but perfect for 2 people and to discover Rome. Trastevere is a really nice place, there are bus stops nearby but almost everything is within approximately 30 minutes walking distance.
The communication with Antonio & Valentina was great, with fast replies and many tips about the best restaurants in Rome. The self check-in (and out) was very easy.
Bonus: we got a message that the studio was ready for us, even before 2 pm.