What I have gathered about gun sight mode:
Leading is very useful to visualize a targets direction and speed,
as it is attached to it and basically displays the current velocity vector.
Trailing is better than leading to align your cross hairs with the target orientation,
since it is attached to your hud and cross hairs will be right above the target instead of in front.
Both are incredibly useful. So why not allow a third mode that does use both at the same time?
Leading is very useful to visualize a targets direction and speed,
as it is attached to it and basically displays the current velocity vector.
Trailing is better than leading to align your cross hairs with the target orientation,
since it is attached to your hud and cross hairs will be right above the target instead of in front.
Both are incredibly useful. So why not allow a third mode that does use both at the same time?