To show how efficient this card is for the right deck, the final versions of Miracle Grow, which were dubbed Super Grow, used Mystic Enforcer as a finisher, since by the time you'd get around to casting it you had an all but guaranteed 6/6 flyer for four mana
Flying, first strike, trample, lifelink, and haste for just give mana on any Spider you play is potentially game-winning, especially now the Spider-Man set has printed so many new tools for the creature type
Since it has to attack to get its payoff, it's relegated mainly to aggressive decks, putting it in a rough position
By the way, Fatal Push will always be a pillar of the format, a great efficient card and the premium removal for all the decks that cant afford to go red