Overall this is a great place to stay and I would highly recommend.
Location: Paolo's place is about a 15-20 minute ride to/from the airport. I highly highly highly suggest you pay for him to pick you up from the airport. It's cheaper than getting a taxi and he helps you get situated with the area and into the apartment. He is very knowledable about the area and gives you a lot of tips along the way as well.
Leading to the apartment there is a ton of stairs so be prepared. I don't mind stairs too much and this was a lot especially with luggage. But the place was beautiful and once your luggage is in the apartment it is managable. We arrived on a Saturday night and it was pretty loud outside. There is a bar right outside the bedroom window which died down around 2am that night. Paolo offered ear plugs to us but we didn't end up using them. The other nights the noise was more tolerable.
The apartment is in a great location as far as being central to a lot of the top attractions. We decided to walk everywhere and it usually took us about 20 minutes to walk to an attraction.
Host: Paolo responded to all our questions and concerns in a timely and curteous manner. He was also very helpful, knowledgeable and friendly. We truly appreciated him during our stay.
Apartment: Overall it was clean and had all the amenities we needed. As with almost all European showers, this shower was also small compared to most American showers. We would definitely recommend this apartment for your visit to Rome!