Its late and I'm sleepy but I'd just like to post my two cents here:
Mega Pinsir is off the top if my head the only viable user of the Move Feint. That's right, that really low base powered +2 priority move that can hit through protect attacks.
and the reason why? Because of Aerilate and STAB actually makes it decently powered and also because priority is everything this generation. And nothing is more satisfying that breaking through an opponent's protect or outspeeding their priority with your even high priority attack. Unless someone can bring up some calc's that quick attack nets certain key KOs, Feint should always be considered and slashed with quick attack in the set list.
Beautifly are my Bishie!
hands off or my Beautifly's shall take you away and have their way with you!