I was looking for a central place but not too touristy. Franco's apartment is in a beautiful old house in a quiet part of Valletta, recently renovated and with all modern appliances. It's a few streets from the island's bus terminal, so I was able to walk or ride the bus easily all through the week. Mid-March is still technically winter, and it can get a bit chilly in the evening; but the space heater and warm duvets will take care of that.
To top it all, Franco has been extremely nice and hepful, booking a ride to the airport, finding a traditionnal bakery in the neighbourhood, etc.
I had an ex-cel-lent stay, and I highly recommend staying there.