Cabal Therapy - Extirpationally Improved?

[GrandpaBelcher]

Cards that increase in power AFTER you Extirpate:
Cabal Therapy

I've been thinking about the interplay between Extirpate and Therapy...

Currently, I'm of the opinion that Therapy is very good.  At least when it hits and when you can reuse it (e.g. you have a bunch of expendable creatures like Ichorid).  Duress is, again in my opinion, superior nine times out of ten because it will find SOMEthing to take.  I don't think I've ever whiffed on a Duress when my opponent has more than three cards in hand, but I've definitely struck out Therapying into a full grip.

Clearly, Extirpating just about anything makes your subsequent Cabal Therapies better unless you have severe astigmatism and are unable to identify the cards in their hand that you get to look at.

Is Cabal Therapy now better to play before Extirpating than Duress is?
Better

• Can now hit creatures (Goblin Welders?  Jotun Grunts?  Dark Confidants?).  Welders and Confidants are usually four-ofs in Stax and UBx Fish, which makes them easy and likely targets.
• Can be used twice--once before and once after Extirpate.  The cost of sacrificing to use it twice is high, though, I realize.

Worse

• Can miss, and misses more often than Duress.  This is significant.

Same

• Get to look at their hand for future Duressing/Therapying and general opponent strategy.
• Puts a card into the graveyard to be Extirpated.
• One black mana.  Cheap!
• Sorcery speed.  If only Funeral Charm (or Piracy Charm!) wasn't selected by the opponent.

I've been playing and improving UB Fish for more than a year now and have had four Duresses maindecked since the beginning.  They currently get sided (in whole or in part) against other Fish decks and Stax, which never has much of a hand so Duress is often dead.  I've already decided I'm running multiple Extirpates, and have begun considering and testing Cabal Therapy in the Duress slot, despite that I will only flash it back under the most dire of circumstances and that I hate the idea of naming Brainstorm when I should have named Gifts (or vice versa).

Essentially, does Therapy's ability to hit more than once and the ability to hit creatures outweigh the drawback of the strikeout, especially now that we have Extirpate to work with?

[dicemanx]

Consider this scenario: you start with a Cabal Therapy and Extirpate in hand. Are you planning on being indiscriminate with Extirpate just so you can have a peek at their hand to make Therapy more potent? For instance, if they play fetchland and use it, will you Extirpate the fetchland? If they play Brainstorm will you immediately target that Brainstorm?

Consider what Smmenen would term "opportunity cost" here as well: one "cost" of playing Extirpate is possibly not playing Duress in its spot (unless you were planning on playing all 3). Duress can also provide the desired synergy with Therapy, and in some instances you'd much rather have Duress than Extirpate in the early game. I understand that Duress might not be so stellar for you in some matches either, but each disruption piece has some sort of drawback. How to evaluate them properly is tough to say.