Upon arrival we were asked to pay 8 euro city tax in cash which wasn't the type of welcome we expected, and this loomed over the entire holiday as the host kept on asking for it. The city tax isn't in the original listing, and we can't understand why this couldn't be done simply through airbnb rather than hassling the guests. In any case I will still provide a fair review.
Pros: Very good location for exploring Valletta and with good public transport link to all the main beaches. The bed is large and comfy. The TV has Netflix and Amazon prime. The evening is very quiet for sleeping. The kitchen is small but has the essentials.
Cons: Style over function - the TV is in the bedroom corner rather than the living room or at least facing the centre of the bed, you hang your clothes in the kitchen which catches all the cooking smell, the bathroom door is glass and facing the bed so you will wake up your other half with light and sound in the middle of the night, you cannot open the window for ventilation as there are mosquitos and other creepy crawlies (a mesh to the window would have solved it) and we found out the hard way by being bitten in the middle of the night. And because you cannot vent the room if you come back from the beach your wet stuff won't dry for the next 2 days (Nov).
You are living in a historic building which has its charm but also all the practical problems come with living in an old building, something to bear in mind with when making a decision.