I found this card very useful only recently and since then i put it to decks right next to the Feint cards. Best events in sphere so far for me. The artwork is somehow strange, cause I'm not sure if the Orc already lost his head, or if he's going to be attacked from behind. And the vampire teethes...looks strange. Anyway. Verdict: 4/5.
Quick Strike
Action: Exhaust a character you control to immediately declare it as an attacker (and resolve its attack) against any eligible enemy target.
Core Set #35. Tactics.

I've never found myself using Quick Strike, despite it's awesomeness. There was a lot of controversy over this an the subject of immune to player card effects enemies, but the confusion passed. Note that it's not restricted to enemies engaged with you, so Haldir, Legolas, Brand, Bard, Dunhere, or any good ranged attacker are great candidates for this. My personal favorite target is Gimli. Muah ha ha haha!
This card is so satisfying to pull off. But then, if I like it so much, why don't I put it in more decks? I was thinking about that recently, and I think I figured out why: the most common point of this card is to prevent an enemy from attacking you (by attacking and destroying it first); but the thing is, Feint accomplishes exactly the same thing but better. With Feint, you don't have to be able to kill the enemy right away in order to stop its attack, and then you can gang up with as many allies as you want to attack it. Plus you can use Feint to help another player, which you can't with Quick Strike unless you have a Ranged character. I think the only advantages Quick Strike has over Feint are 1) being able to trigger your "when this character attacks/defeats an enemy" abilities whenever you want, and 2) being able to attack quest-related enemies early to advance the quest before the combat phase. But from my experience these two situations are few and far between enough that I've always been happy to draw Feint in almost every case, while so many things have had to go right in order for Quick Strike to be useful for me when I draw it.