I would round out the broken list with Sol Ring, Library of Alexandria, Mana Vault, Mana Crypt, and Ancestral Recall
The last time this came up for me, a player was casting an Underworld Breach that would end the game
Sram's ability resolves before the spell that caused it to trigger
Drumbellower offers a portion of Seedborn Muse in a new color
They might not be a meaningfully supported archetype in most sets, but you still find them, often as a boon for doing something simple like triggering heroic on Phalanx Leader, to juicing up a card like Ancient Animus, or just to make an aggressive deck more viable
Except its not symmetrical and you have to pay an energy for each creature you put into play