Positive side:
The pictures represent the place accurately.
it's spacious, well designed and a nice place to be at for longer times.
The location of the place is great, only a few minutes walk from the coast and a short walk to nearby park and a street full of restaurants and bars that leads towards the main center.
The apartment was really clean (except for a few places were you'd usually not look) and you've almost everything you need at your disposal for a long or short stay.
Downsides:
The communication with the host(s) was average. We were greeted by the male (spoke barely English) and gave us a quick tour of the house showing us how everything works. They told us we'd receive information about the trash and changing bed sheets every week, however they did not contact us at all later on. Through text, they seemed uninterested and fairly curtly.
As others have also mentioned the apartment is right next to a construction site,
during my stay I've been woken up about 6x, around 8am by insanely loud drilling noises right above the appartement.
Palermo in general is fairly noisy, the location of the apartment was however at the quieter part of the city.
Besides the day's of the construction work, i was able to enjoy a good night's rest as an average to fast sleeper.
Conclusion:
All with all I'd be eager to stay at this apartment again, assuming the host will use the few hints for small improvements.