This was further reinforced for me when the recent security procedures were inflicted on our long suffering customers and much more (almost all) baggage therefore went into the holds. The computed (mcdu) Vls much more closely matched the PFD (FAC) figures because the load form/sheet was suddenly more accurate.
Because our guests are now permitted to bring their huge trolley bags on board again, the figures tend to disagree.
As an exercise if you have a minute in the cruise, work back from the PFD Green Dot figure, via the QRH 4.01 to see what mass the ac thinks it is at and compare with the ECAM figure.
Cheers all,
mcdhu