Punishing Shot vs Power Spike

With my points taken into account.

Power spike: If target foe is casting a spell, the spell is interrupted and target foe takes 75 damage. Recharge 15, energy 10

Punishing Shot: If Punishing Shot hits, you strike for +17 damage and your target is interrupted. Recharge 5, energy 10

Well Power Spike only works against spells, preparations, bow/melee attacks, stances, shouts, skills, and signets won't be effected. However, we can all guess that elementalist or monk is casting a spell. Plus, it has the upside of the inability of most to interrupt enemy's attacks unless long timers. I've spammed savage shot at the exact moment a person began to cast a like 3 second spells, and the action of knocking an arrow, drawing back, and letting go, then the time to arc, the spell got off and the attack was wasted, all very annoying.

Has any of you actually got 'Punishing Shot'? And if/when yes, where did you get it???

If you're a mes prime, you definitely want power spike (although power leak is probably better =p). Sure, it recharges slower, but the 1/4 sec cc means you can actually interrupt quick spells if your timing is good. Punishing shot has a 3/4 sec cc plus arrow flight time, so you'll never catch anything with less than 2s cc using that.

As a ranger prime, expertise might make punishing shot worthwhile. Possibly. Except it's still elite.