Thats a pretty wicked advantage, especially considering this location has five will power, making it pretty tricky to take out
Where Six gets exciting is its second ability during your turn, nonland permanents in your graveyard have retrace, an old mechanic from Eventide that allows you to recast spells from your graveyard if you discard a land in addition to paying their costs
Combined with Exploration or Fastbond, the Horn quickly becomes an engine from which you can draw three, four, five, or more cards a turn, at no cost
This still applies today since these cards will never see another printing thanks to Wizards policy on the Reserved List policy
Dredge has on occasion played Steam Vents to be able to cast Narcomoeba and Prized Amalgam, but this gives the deck access to an instant speed dredge that can also be picked up with Life from the Loam