Being able to do the effect at any speed makes the card quite tricky and pushes it into the realms of playable
Previously, these filled the role of being the standard set booster pack used to build decks and casual collections
As we can see in many Hammertime decks, it is often the only reason to play black as it is so good at slowing down anything your opponents might be doing
There's so much looting and rummaging that you get to churn through your deck quickly, reducing variance and making sure you find the cards you need (and discarding the ones you don't) reliably, WITH ONE MAJOR EXCEPTION (see The Bad) It's very consistent
I frequently used Shared Summons to grab two of the combo pieces in my Yisan, the Wanderer Bard deck to go big on the following turn with Quirion Ranger and Scryb Ranger
If I cook something in Witch's Oven and make a Food, thats a two-part ability