Giulio's pad is truly one-of-a-kind. My wife and I stayed for 4 nights, and I don't think I could have asked for anything more. The space is very clean and orderly, with nice furnishings and a very big open space/tall ceiling. Easy to find and get in without Giulio there, and he was very responsive.
The apartment is located on the edge of Trastevere, bordering the river. The location is perfect for eating out without an overwhelming tourist influence. Great options within walking distance. I found it strange that the place was so very quiet at secluded, yet right in the middle of nightlife and strolling options.
For the tourist sights, it's about a 15-20 minute walk to most of the major attractions, although some are as short as 7-10 minutes. We walked 25-30 minutes to the Vatican. There's a nice walk no matter which direction you take.
While there's no subway station nearby, the H bus, and to a lesser extent the 8 tram, can take you into the heart of Rome and out the other side to the Termini train station or Borghese Gardens. The stop for those is a mere 75 yards away.
If I'm back to Rome soon, I will definitely be coming back to this place. Thanks, Giulio!