Like most Magic: The Gathering cards, the value of Chart a Course depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Secret Lair Drop)
Doubling effects will compound and you draw a total of four cards per normal draw
And youre packing all those cards in your Shorikai, Genesis Engine EDH deck already
Some players prefer Sealed because they arent required to make quick deckbuilding decisions on the fly
Better yet, due to how Replicate works (the copies go on the stack individually and resolve individually), counterspells are useless against it
Menace I believe is an underrated ability (I might have said that earlier) and it makes things much harder to block