The apartment is indeed a gem - very spacious (way bigger than what can be perceived from the pictures), well equipped, quiet and kids friendly. It is also cool in the hot days - all the bedrooms are with AC. The living room does not have one, but the rest of the ACs keeps it cool as well.
There are more than enough good restaurants in walking distance and the nearby shop has everything that you might need.
It is also perfectly connected with the rest of Malta - the bus from the airport stops 100m away, and the other buses that stop there can take you directly to all the other main points in Malta.
Communication with the host was also superb - Justine was eager to help us and interested in the quality of our stay the whole time. She also replied very quickly.