This is basic engineering paired with physics. It's a great topic to go do some design research on. I, myself, typically don't deal in perceived differences, seat of the pants, feels like, or any other unsubstantiated data. It requires a specific minimum air pressure to support the weight of the car. Once this pressure is achieved (assuming the air bag is not already expanded to the limit of it's optimal max volume shape) additional air primarily adds to the volume. The minute amount of additional air pressure is attributed to what's needed to change the shape of the bag as it nears max volume shape. As long as you aren't going to the extremes which starts to limit your total travel, the ride quality remains the same because the spring rate stays nearly the same. Spring rate plays just as much a factor in ride quality as dampening rates do. Again, you don't "have to lower the pressure quite a bit just to get a change height". The RAM1500 is a prime example of this. It's driving modes can adjust ride height by as much as 2.5". According to conversation with their engineers, the difference in spring rate between their lowest setting (Aero Mode) and their highest setting (Off-Road 2 Mode) is only 10%.
All that said, if Tesla is pushing their bags to the extreme, and significantly reducing travel to achieve these extremes, that could definitely cause things to feel harsher. The biggest reason people most likely "feel" that the ride is harsher at Very High, could be simply do to the slow speeds they are moving at that setting. At slow speeds, the suspension tends not to move as much, which means that it doesn't absorb as much of the ground impact. At the Low setting, there is a perceived stiffening of the suspension by some, which makes it "feel" harsher to them. The mind is an amazing thing to convince, even when we have data to prove otherwise.
Thanks. I will not be buying the air suspension since it does not improve comfort.
