And it's not just the ATA length itself making the bow more steady that's the entire advantage.......the longer ATA lengths are much more user friendly with repsect to geometry and form. It's much easier to find a good upright posture and still maintain your anchor references with the shallow string angle of a long ATA bow.
I've come to realize that at 6'3" I almost NEED a 40" bow to get a proper form fit.

These longer neutral or deflexed riser bows also have a different weight distribution for the most part which puts the majority of the weight above but also (like in the case of my Constitution) BEHIND your hand. This weight distribution patern makes the bare bow want to roll TOWARD you at rest. This allows better compatibility with longer target style stabilizers and sighting systems without overpowering the fall of the bow in a forward direction.
In other words you don't need as much BACK weight and can use heavier or longer stuff out front and still wind up with a bow that doesn't want to "dive".


Longer 'Target" bows also generally have a higher brace height.