Thanks Owain,
sounds good. Would be nice to see how it is on 319 and 318, but I'm not flying them.
About the 1 kt/1000' (or more) I think that it is the reason that the 321 looks heavier at high altitudes than it is.
On the 320 if the weight entry is correct you can fly 2000' above the FMGC calculated optimum FL, on the 321 it is maximum 500'.
On 321 the max recommended FL is unreachable.