Is it just me, or does Pooka look weak? It can only trash 6 cards, and +4 Cards doesn't seem that much better than Spice Merchant. I think I would almost always buy spice merchant over this unless there's no solid draw.
It's just you. Pooka is crazy strong — it's a trasher and early game engine component in the same card, but if you have extra +buy, it can remain an engine component for the entire game. It also gives you a lot of cycling which makes the trashing faster than you would expect especially if you also have another trasher that can get rid of the Curses.
I'm still not seeing it. It costs
so it's not going to be picked up super early unless you use Cursed Gold or get 5/2. Once you've used it 6 times it's generally a dud, unless you have extra buys to make it basically a Smithy. The cycling is a good point, but it would also make Pooka miss the shuffle more, right? All in all, it seems like a good early game
but obsoleted in most late games and weaker mid games.
EDIT: Comparing it to Stables is interesting. The big question is it worth the trashing to downgrade to a Smithy? I think not, unless it's the only trashing on the board.