My girlfriend and I stayed in this apartment for 5 days, and we're really happy we did. The apartment itself is nice - it's clean and spacious. But, even better is the location. It's a perfect walk to nearly everything in Rome, and the nearby piazza (Piazza del Popolo) is a beautiful, spacious, lively place. Walking through it is an amazing way to start or end your day, or spend a relaxing few hours with a picnic lunch. (In fact, we picnicked in the Piazza each day we stayed there!)
Giacomo is really kind - he met us when we arrived, and came to say goodbye when we left. He was also always available if we had any questions, and checked in on us mid-way through our stay. He also let us store our luggage in the space for a few hours after we checked out.
My one comment would be that the internet is a tiny bit shotty, but worked perfectly for the majority of the time. And, also, because the apartment is on street level, it's a little loud in the morning. Mostly just Italian men chatting while moving their cars around 8 am. It was really no big deal, and would only last 5 mins or so each morning, but thought I'd mention it incase that's a major concern. All in all, my girlfriend and I would both recommend this apartment.