I have recently been there with my family Via Air BNB.
The host, Sergio was very nice and spoke English well.
He took us out to show us around the block, show us the nearest supermarket and gave us some recommendations for where to eat and what to do.
The flat is 5 minutes walk from Piazza Castelnuovo which is quite central and where you can get buses to many places (including to the airport).
It's about 15-20 minutes walk from Teatro Massimo and the entrance to the old city and about 30-40 minutes walk from the train and central bus station.
The flat itself is very clean.
4 room, each one with a private bathroom and shower (which are modern as well).
The rooms are all large but 2 are especially big.
There is a lot of noise coming through from the street and from inside the building but it's less noticeable in the bedrooms.
Overall, a great experience and we would be happy to recommend this :-)