Quote from arrogantAxolotl »
The two cards, while not identical, are still incredibly similar. Players aren't playing Fa'adiyah Seer already (because it sucks), and it would be unreasonable to believe that players are suddenly going to start playing Dryad Greenseeker en masse for the same reason. It's a crappy card, and players will turn to other alternatives if they want some kind of land-drawing effect.
Dryad Greenseeker isn't a land-drawing effect; it's a card-drawing effect.
That is, if you run Fa'adiyah Seer, you will draw a bunch of extra lands and no extra non-lands. If you run Dryad Greenseeker, you will draw fewer extra lands than with the Seer, but you will draw extra non-lands, because you'll only draw a land for your regular draw step if the top two cards of your library were both lands before you activated Greenseeker.
If we're comparing effects, Greenseeker is a lot closer to Courser of Kruphix (but without the life gain or the synergy with other forms of conditional draw) than it is to Fa'adiyah Seer. This may not mean it sees play anywhere — it's clearly worse than Courser — but that's the relevant comparison.