Why? Why why why why why? Why is there a worse-in-almost-every-way Llanowar Elves? I understand that if they printed only good cards, we would have massive powercreep but still, why?! The reason I say this is only worse-in-almost-every-way is that it can survive an unsacrificed Disciple of Tevesh Szat whereas a Llanowar Elves will die. But the extra point of toughness doesn't really matter in the long run since odds are you will neither be attacking or blocking with your mana base. It also costs twice as much as Llanowar Elves. Even though that's only 2 mana, that's an extra turn you have to wait before you get your extra mana which can easily destroy your tempo..
Pros: Tougher Llanowar Elves
Cons: More expensive Llanowar Elves