Carmen's place is great.
The exterior appearance of the building is scary. It is almost like walking through a bad neighborhood.
But the inside is the opposite. The building is great and her apartment is excellent. It can be seen that she's a professional host. The room is well setup and the WiFi is good.
Personally I won't visit Rome again because the public transport is poor compared to the rest of Italy. But if somebody wants to stay near Termini, this is the place to stay.