The apartment is large enough for 4 persons. In 5-7 minutes (walking distance) you can reach the beach, (st thomas bay), the city centre and supermarket. The beach is small but it is a partial sandy. Marsaskala is a small place, but you can find restaurant, cafes and bars. With the buses mdina and valetta can be visited (take your time, the buses often come too late).
John is a great host, he informs you about everything you have to know. The check in and out was without any problems. He organize a taxi for us. Thx john.