We had a great time at the Palazzo. The building itself is stunning and it is located in a very central position in Valletta. Rooms are clean and tidy. Breakfast (included) is not amazing but gets the job done.
We had a couple of minor issues, first at check-in when the keys could not be found, then again when we had to move room (which was planned) and had to wait a while in the common area as it wasn't clear which room we were supposed to move to. But in both cases Jacques was very nice and helpful and the situation was resolved in a reasonable time.
All considered, we'd recommend it: very atmospheric and great value.