Catania is wonderful and offers a lot of things to see, to eat and to "feel"! Many historical places where you really have to go such as Teatro Greco, Monastero dei Benedettini, Cattedrale di Sant'Agata and places where you can touch the true atmosphere of the city like the A' Piscaria (Fish market).
Apartment is right in the middle of Via Etna where you can easily do shopping or have a coffee and something to eat (Arancine, Granite con Brioches, Pizzette, I mean whatever) and they taste like heaven. I suggest to stop by "Da Savia", just go there and you'll understand it's even very close to the flat.
Good for couple and small families, apartment have everything you may need for your stay. What else?
Maybe mattress is a bit old but hey, for this price is definitely more then enough!
Very beautiful trip!