Casper (post no.37) says Tiger is doing better because it is flying at lower flight levels (implying higher weight and therefore pax loads) compared to
VB and QF which he often hears at F400 & 410 (supposedly less pax etc).
FYI A320's have lower cabin diff. (due to thinner fuselage skins and structural strength I guess
) than the B737's now in service with
VB & QF. Therefore they are limited to F390 (according to my googling). I would therefore discount flight level selection as an indicator of profitability
