One other characteristic of mixed-mode is its resiliance to strong headwind
The major airlines have a big problem with the robustness of landing rate at Heathrow in strong winds. Mixed mode is seen as the holy grail of maintaining a constant movement rate. However at Gatwick, when the wind is strong the movement rate goes up by maybe 10%. When mixed mode is introduced should we endevour to provide a consistent movement rate or an expeditious one?