It lets you reset with an additional draw on top, which can completely turn a game around if you were starting to struggle off the top of your deck
So unless you already have most of the cards, this ones worth picking up
Thats not to say that you wont find powerful cards in a Set Booster indeed, each pack of 12 cards (plus two bonus, non-game cards such as art cards) contains 1-5 cards at the Rare or higher rarity level, making them a more appealing product in some ways than, say, Draft Boosters
You can return any card from your graveyard to your hand, and thats why it sees heavy play in EDH
Though somewhat costly at six mana, this simple yet stellar green enchantment states that each of its owner's lands may be tapped in order to produce a treasure token