I greatly enjoyed my stay in Rosa's appartment. They are really tidy and comfortable, the interior in the room is fresh and new, there is everything, that I needed in the apartment (air-conditioning, wi-fi, comfortable kitchen). Rosa was always helpful (she explained us where are good places to have dinner, to buy local food, to go to beach, helped to find transfer, answered all our question and was eager to give everything we needed).
It should be pointed, that the apartment has good location - in the center of the city, the main street with lots of restaurants and bars is in two minutes (while it is quite in the night in the area of the apartment), there are lots of supermarkets close to the apartment.
Castellamare del Golfo is a great choice for Sicily visitor - it is close to Zingaro, Scopello, San Vito, Alcamo, not very far from Palermo (1,5 hour using public transport). Still, the city is not very "touristic" (in the bad meaning of this word) - has lots of local restaurants and shops, that are used by Italians, the streets and the beach are not overcrowded.
So, visiting Sicily, I would recommend to choose Rosa apartment, due to great comfort, helpful host and great location.