Yeah, but those "particular cases" are not just other stuff that happens in Dominion---they're part of the card resolution itself. Putting +1 Card instead of +$1 (that translates into +1 card at the end) on Storyteller is a big difference because Storyteller immediately uses that card in some number of cases (that translates into more stuff after resolution).
Well, it is
a difference. And it's a difference that's exactly equivalent to +1 card sifting up front before resolving the rest of the card. So I'm not sure what the big controversy is here.
Some people were calling it a "very, very big difference" whereas to me it seems far more modest, like playing a Pearl Diver. Yeah, occasionally that Pearl Diver will line up something awesome on to the top of your deck that leads to even yet more awesome things happening that couldn't have happened if you hadn't gotten that awesome thing closer to being in your hand. But this level of sifting usually doesn't make that big of a difference.
Since some people don't seem to appreciate analogies like this Pearl Diver one that won't exactly hold in every respect, let's come up with something that concretely does hold in every respect (well, provided you have at least 1 non-treasure in hand, but I'll call that a quite safe assumption for a sifting effect discussion and have no interest in your other cases)
Storyteller: Action, $5+1 Action
+$1
Play up to 3 Treasures from your hand. Pay all of your $; +1 Card per $ paid.
Storyteller-sifter: Action, $5You may immediately swap one card from your hand with the top card of your deck.
+1 Action
+$1
Play up to 3 Treasures from your hand. Pay all of your $; +1 Card per $ paid.
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Is there a big difference between these two cards? I'm saying no. Certainly not a "very, very big" one as someone was hilariously claiming.