This helps multicolor decks get the best basic land, rather than having to guess on turn one
Similarly, Doc, Leader of the Seven Dwarfs lets you play characters for one less ink when he quests, which can be useful for cheating out Happy, Good Natured a turn early
We're also replacing Heihei, Protective Rooster with Chien-Po - Imperial Soldier, trading one lore for two Willpower
Based on the data I do have, it seems to be between 0.5 and 0.55 Mythics you can take per draft, though it should decrease as you get closer to the Mythic Point
Once stocks run out, that is it
It's also worth noting that AncestralMTG has the capital to purchase large collections and can offer you higher prices on your high end cards