Jelena's place is very well located in a residential area of Valletta, however it is still very close to bars, restaurants, and the bus terminal (no more than a 10 minute walk). We also arrived quite late and jelena kindly arranged for us to be let into the flat after 12am.
The apartment has everything you need, including a great aircon, which makes sleeping in the Malta heat bearable.
There are some shops near by but no main supermarket so it can be difficult to find food to cook - however this is true of all of Valletta for some reason, there are supermarkets at nearby sliema.
Also, if you are a light sleeper I would advise bringing ear plugs as cars beep loudly outside every morning - again I think this is true of all of Valletta, not just this area.
Would definitely recommend staying here