We liked our stay at Geert and Veronica, they are really flexible and communication is perfect.
We worked in the apartment, we can confirm wifi is working well.
The apartment is clean (even if wear signs on walls and equipment) and well equipped.
You should be aware that the apartment is close to a big road, which is a good point to go to Valetta quickly, less good if you stay during the day at the apartment for noise and view.
The terrace is a nice place to take a coffee.