This place is as nice as it looks in the pictures. We stayed for a week and having a place to cook and wash our clothes saved us money on both food and luggage. It rained very hard one day, and despite being from the 16th century, there wasn't a single leak anywhere. Reasonably fast Internet, and the TV's with Apple TV kept us entertained once we were ready to kick off our shoes for the day.
Mickael was a great host; he thought of everything! He even arranged a ride service to and from the airport.
The loft is also extremely conveniently located. The palace armory museum is just up the street. The Victory Bell, Barrakka gardens and the three cities ferry are right around the corner. There is a small grocer up the hill where you can stock up on anything you will need.
One thing to note, there is a siren that goes off at around noon that sounds like a storm emergency siren but it's not. I think it's actually from the war museum or the upper gardens (they fire off the cannons at noon). You can hear this pretty much anywhere in Valletta though, not anything to do with the loft specifically.