I think this card is really great.
People forget Crack Shot is not only useful when you get to use it, but is also a good token stripper when you don't.
Because you get to use it AFTER the opponent modified his defense dice.
Often a crack shot ship (even a single one) firing first will get the opponent to use a defensive token to avoid getting hit if you discard the Crack shot card.
In this case you dont "use" the card directly, but it still benefit you when attacking with your other ships on the same target (or defending against, if it discarded a Focus).
Edited by Giledhil