Where do I begin?? Staying at Guido's apartment in Trastevere was an amazing experience! I went for two weeks to celebrate my 40th birthday and it was life changing - in large part because of our stay in this apartment.
The location is absolutely perfect - easily walkable to bars, coffee, restaurants, beautiful views, and an outdoor market. We walked into Rome (proper) from the apartment daily quite easily but the bus and tram are nearby if you don't want to walk as far.
The apartment is small but very quiet and comfortable. We slept in the bedroom and had a friend sleep comfortably on the pullout couch in the living room. The AC works great and Guido has everything you could need there. The shower is tiny but had great water pressure and consistent hot water even after consecutive showers. Guido is an amazing host! I can't say enough good things about him : first he's incredibly helpful (arranged several rides for us over the course of two weeks, helped with a small ant problem the moment I notified him about it, and was just generally awesome), he responds to texts quickly and was readily available for anything we needed. Also the complex where the apartment is located is in a gorgeous and secluded community of sorts tucked away enough to feel private while still being a 2 minute walk to Big Star (a coffee bar that became our daily go to for great cappuccino!).
The only only caveat is that there's a large number of steps up to the apartment from the street, so if you have any mobility issues this would not be an ideal match.
Overall, I would highly recommend Guido's property for your stay!