Inertia dampening uses less power than override at equal thrust.
d1ag0n#6984 noticed this one.
In the attached video, I have navigated two grids into an equilibrium of gravity and thrust. The atmospheric thruster on the right has thrust override set at 100% while the thruster on the left gets set to 0% (disabling override).
The overriden thruster uses 2.4 MW to bob around at the test altitude. The thruster which uses inertia dampening only draws ~0.8MW to hover at the same altitude.
Given that both grids have the same mass and the same maximum thrust, they should both use the same amount of power - but they do not.