the left shoulder button kicks in at a little more than halfway down if youre using it for an airbrake, so theres probably about a hundredth of a second of difference when pressing it down compared to the right one. why they didnt make the right one analog is beyond me. maybe the wiring will only support 4 analog signals, maybe they couldnt figure out how to fit another analog button in there (unlikely, ive had them open and i dont remember a lack of space on the right side). Maybe they didn't want to lay down the extra money for another analog dial. That little cost margain may be the answer