Overall the apartment is OK if you can stand the noise from the street (with earplugs for instance) . The apartment was cleaned and with everything we needed for our stay.
The location is very good if you plan to visit the Vatican and St. Peter. It's not the best location in Rome, but still very central and you can get to everyplace by foot. The street is super noisy. The windows are old because it's an historical building (they plan to change them soon but it will take some time), so they are not noise canceling. So either you don't suffer from noise or bring earplugs :)
Two things you may want to notice, there is no elevator (but it's only 1st floor) and no washing machine and dishwasher. We did not notice before booking and were a bit disappointed (even if it's written in the description).
Chiara was great. Helpful, communicative, nice and ready to help.