The neighborhood was pretty standard, but it was close to the Colosseum. If you want to see other historical sites (Pantheon, Spanish Steps, etc) it is a bit of a walk, but doable.
The apartment was very clean and nice but also fairly small feeling (both my wife and I are around 6ft (1.8m) tall and had to watch our heads in a few places). Also, the shower was a little small and didn't have a curtain so everything in the bathroom tended to get wet whenever you took a shower.
The host also left a very helpful booklet of restaurant suggestions and things to see in Rome. We found this to be a great resource while there. She was also very helpful in arranging taxis to and from the airport.
Overall, very nice, but the shower and far walk to historical sites other than the Colosseum and Forum/Palantine Hill were downsides.