The apartment is located in the historical city center, which is also the "party neighborhood". This wouldn't be a problem if the apartment would have double glazing windows, but this is not the case. Expect to hear music (and loud people talking in front of the building - there is a kebab/pizza where the young party people go at 2AM for some food) until late hours.
The apartment in itself is very clean and everything is functional for a couple as it should be. The bathroom is somehow ridiculous big in comparison with the rest of the flat.
Wonderful Italy is a company with hundreds apartments in Palermo, so don't expect the classic old school Airbnb, but rater a company who tries to offer you tours and other things once you arrive.
All in all the apartment is OK: it's clean, big enough for 2, has airco, it's really central and good price-quality. But be aware of noises, and the impersonality of the airbnb.