It takes a few rounds to understand what the cards mean and how they interact, which is a little annoying since its the point of the game
You can use it to fix your draws, and using its ability to check the top cards in your library can also let you know whether you should use a fetch land or other effect that will force you to shuffle, or if you should draw one of those cards first
Mortuary Mire has a new lease on life, no longer having to compete with tri-lands and fetching up Battle lands
The card exiled by the second mode is exiled face up
6 Ezuri, Renegade Leader The Elf, The Myth, The Legend There is a lot of mystique about what really happened with Ezuri, Renegade Leader, but whether he was a hero or traitor of the forces of Mirrodin is irrelevant, since he has such a powerful card
It makes much more sense to play this card alongside proliferate, as we can double all these counters and keep the engine going