My girlfriend and I stayed in Cynthia's apartment for 1 week in August and loved it! The apartment is situated in a quiet, upmarket part of the town, however is only a few minutes walk from both Sliema and St Julian's Bay. Perfect location!
The apartment was very clean, had all the amenities we required and the air conditioning was excellent (essential when you're Scottish and it's 35+ degrees). The courtyard was also really handy, providing a nice place to sit and have a beer...or three.
Cynthia was great! She collected us from the airport and was extremely helpful in providing suggestions for restaurants, activities and travel. She also helped us arrange a taxi back to the airport for our departure flight.
Overall great trip, friendly hosts and excellent place to stay. Would visit again.