I never actually figured out a time to bring it in, so it would probably be better as Imprisoned in the Moon as another way of dealing with planeswalkers, or even just more counterspells
This thing stops you losing to practically everything, except for mill, win the game effects from opponents, and the very rare instance of someone stopping damage prevention and hitting you for 21 Commander damage (your life total wont change, but youll still take the 21 marked damage from a Commander)
Stone-Throwing Devils isn't a card that broke MTG in half, but Wizards of the Coast was right to remove it
Some people might say that it fizzles
Your mileage will vary, but with card sleeves alone you should be protected from most of the hazards associated with playing on a kitchen table or a bench at the local game shop
So, would you delay your Cultivate to drop your five-cost Commander next turn