We stayed at Piero’s apartment in Nov’19. Location is great - right after the Vatican and near the metro station.
The Piero’s place is lovely and clean, everything you need is there.
Everything was fine except 2 details: the door downstairs is vey hard to open (maybe the key is broken, or the other reason); the housekeeper doesn’t speak English well, but it’s not really a big problem. Also, if you consider to use a coach at the lounge as a sleeping place - ask if has been replaced, the one we used was broken (it was creaking and uncomfortable).
So, I would say it the perfect place for 4 people near the Vatican and other significant attractions.