You know what they say about what is important with real estate: location, location, location. Claudia's place is absolutely perfect on that front - if you think about Rome city center, the farthest place to see (Vatican) is 20 minutes walk away - everything else is closer than that.
As for the apartment itself, it is exactly as shown on the photos, very comfortable and clean. We were 4 people (2 adults, 2 kids) and our stay was great - Claudia's place has 2 bedrooms, which is pretty important. Quite a lot of apartments have 1 bedroom and a sofa, which is theoretically ok for 4 people, but having 2 actual bedrooms is way more convenient, believe me. Sleeping on a sofa is ok for one night, for a week - not so much.
We had great contact with our host (Marco), although I also have to say that we didn't actually need it that much - everything worked perfectly. Marco met us when we arrived, then he also arranged our transfer back to the airport and that was it. Throughout our weekly stay we had absolutely zero problems that we would our host to help with, so in that regard it was also an amazing holiday.
All in all - if you want to see Rome, especially the city center, this is absolutely the perfect place.