Marco and Gloriella are very hospitable and caring. They organized transfer for us to/from airport (even it's an inconveniently for them), we're ready to organize a visit to clinic and satisfy all our requests according apartment. Also they gave to us a lot of advices about sights, transportation, shops and gifts.
According the sppatrment: it's the same as in description - one (king-sized) bed, sofa in living, fully equipped kitchen and bathroom (but with small and rather specific shower cubicle - sometimes it can be hard to regulate the temperature of water).
About place - Mondello is in 20 minutes away from Palermo, there is one regular bus which goes every 10 minutes, so it's very easy to get there. The beach in Mondello is rather crowded (especially on weekend), but the sea is crystal clear and blue (from the apartment it's takes around half an hour to get to the beach by foot). Also i'd like to recommend you rent a car, because on Sicily it's very hard to get to the somewhere by public transport and then get back (except the nearest places like Palermo or monte Pellegrino).
To resume: I totally recommend this place for quit beach vacations with cultural program in Palermo. Without any doubts recommend to stay at Marco and Gloriella's place.