Impetus can be good, but it is still nerfed by the miss reset, so it's random how much benefit you get from it if any at all. And that benefit/chance lowers quickly as the difficulty of what you are fighting increases, so it's an ability that makes you weaker vs stronger enemies (comparatively).

Footwork certainly is good, but once again, long recast and low duration.

The inability to engage while Boost is active is yet another indication that it is fundamentally broken.