We stayed in Villa Diamantina for 10 nights in March-April this year. We were impressed at being welcomed at the villa in person even though it was late at night when we arrived, we were given a tour and shown the amenities, then we settled in.
We had a lovely stay, the villa is nice with modern facilities, took us a while to get the hang of the solar heated water system, but it is actually quite simple and the showers were hot and powerful. The private outdoor pool was fab but freezing due to the time of year we stayed. The shared Indoor pool facilities were good, especially for the children but unfortunately we shared it with a 'messy' family for half the week which was disappointing as it meant it was out of action for a couple of days for health and safety but this was responded to politely and effectively by the management after we reported it. Kitchen was modern and clean, could had done with some complimentary condiments and slightly better utensils as we have wanted to do mostly self catering. BBQ facilities on the patio was great. The villa was over 4 floors; basement housed good play facilities for children and adults 2 bedrooms and basic bathroom , ground floor was living room area, kitchen, family shower room and access to outside, 1st floor 3 bedrooms and family bathroom, top floor master bedroom with beautiful views over the other properties, en suite shower and access to roof terrace. Each room had a balcony which was great. Roof terrace is huge with seating and washing line. Stairs to basement and top floor are steep, wooden and 1 is curly, wasn't easy for young children or Grandma to use. TV was limited for English guests. Night times were quiet in the local area, you can feel it is a residential area, which was good for the family.
Local residential area was steep hills, but nice views and quiet. local bay with beach and shops is walkable, about 20 mins. Bus service across Malta is excellent and cheap, but you need to go to Valletta city bus terminal to get a timetable and route map.
Water Park was closed 'out of season' which was disappointing but we visited Marine Park to watch the sea Lions and Dolphins shows which was great, especially out of season as it was quiet for visitors. Blue Grotto is worth the day trip, beautiful views from the little boats. Be careful if using the Sightseeing bus tours, they don't run late and don't warn you of last pick ups, local buses are better, you just buy one ticket to use all day.