I don't know where you guys are from (frankly not even sure what planet) but in NA, "legacy" carriers pay you by a formula which includes number of pax and weight of airplane among other factors. Size does matter when you work at a place like that unless there is something called status pay which I believe BA has. In that case, size does not matter. And size does not matter if you work for WJ where there is only one type. There are arguments for and against both status pay and formula pay. I tend to like the stautus pay system but will probably never see it at AC.