They're not as good here as they are in the early days of the TCG, and in the early days of the TCG, they were barely any good at all
People throw these kinds of claims around pretty lightly
Cards that would go to your graveyard still will, even while your graveyard is a creature on the battlefield
(2021-07-23) If you somehow venture into the dungeon while a room's ability is on the stack, you will continue on in the dungeon
Biggest Omissions: Sliver Legion $39.99 Glimpse the Unthinkable $34.99 Tezzeret, Agent of Bolas $21.99 Fulminator Mage $19.99 Maelstrom Pulse $17.99 Gaddock Teeg $17.99 Huntmaster of the Fells $9.99 Kitchen Finks $9.99 Nicol Bolas, Planeswalker $8.99 Knight of the Reliquary $8.99 Lightning Helix $5.99 Boros Charm $1.99 Fulminator Mage would have been nice, but it was just printed in Modern Masters 2015 , and (Tarmogoyf excepted) it seems like WotC has been good about not printing the key cards from one Masters set directly in the next
You stockpile them and they persist across phases and turns until you spend them
