Our stay at Flavia apartment was great.
The rooms are actually bigger than it feels from the pictures. During the day there is no direct sun into the windows which is from one point good during the hot period, internal lights are more than enough to feel comfortable.
As the apartment maintained through the host-service company (which is a big plus for me) organization of all the aspects of our stay went very smooth: we were easily supported with late check-in (plus our flight was delayed), credit cards are accepted for payment, all linens were from dry cleaning, easy check-in/check-out
The location is really good – easy to reach lots of places of interest by foot (coliseum is 10min walk), main metro line entrance point in 3min walk plus bus lines to reach out of metro range areas, Termini is in 15min walk; just round the corner from the apartment perfect bakery (in fact from variety and freshness of bakery products we didn’t find anything better in Rome). The district itself is quiet, with two supermarkets nearby
The only thing to mention about the apartment is that the sofa in the living room could be too soft for adult person (for our child it was fine), bed in the bedroom is fully ok for two adults.