I spent two nights at Angelo's place and could not be more than happy. I know Rome quite well, but being in the heart of the city definitely helps to make the best of it.
The location is super central, close to Repubblica subway station and Termini station (useful for those coming from the airport, I can witness), within walking distance of the main points of interest but still in a residential area, so close to the basic services--pharmacy, supermarket, etc. The building is very new and has several elevators and the constant presence of the concierge both day and night make it even safer.
Besides being a comfortable stay (I swear, I didn't want to leave my bed!), I must also say that every corner of the house is really beautiful. One notable detail is definitely the floor: unique.
In short: I couldn't find any negative aspects, despite the heat of Rome. Thank you Angelo! I will definitely come back