I had a pleasant stay at Christine’s.
The location is amazing being less than 10 minutes on foot from the airport (and right next to a bus stop into Valletta.) Despite this it’s really quiet.
The bedroom was very clean but be aware that there are 3 guest bedrooms in total (let separately) sharing 1 bathroom. Christine does not live in the flat which is entirely rented out, so I never met her and you do miss the nice Airbnb experience of actually talking to a host. Having said that, communication was good and self checkin / checkout was easy via a keybox.
One other thing to note is that the bathroom does not have a shower but only a bath with (sit down) shower head.