The appartment is spacious, though the kitchen is a bit small compared to the corridor.
Charlie is a very good host, he will answer any question and quickly as well.
The appartment is within walking distance of Rabat, with some nice shops, and Mdina, which is beautiful.
To explore Malta you might want to rent a car, which is not really expensive (Charlie can advice you on this), unless you´re visiting Valetta (in that case I would advice travelling by bus).
If you like shopping, Attard is a good place to do so (better then Valetta to be honest).
I would recommend visiting Blue Grotto; breath taking.
Dirk & Annita