Well, Dromokas Command can fight the creature you need to kill or protect your battlefield from a sweeper like Anger of the Gods
Still, as long as I had a bunch of them in my deck, the upside of a free spell is worth the inherent risk of putting a colorless land in my deck
Truly, the possibilities for a really strong deck with these cards is endless, but for players who like to Party, Garland at the Chaos Shrine looks like the best scene box to pick up.
I probably play more enters-the-battlefield tapped lands than most folks, since my local environment with the other RC members is pretty slow, so I see how Tiller Engine might be something that I get a little extra mileage from
The lifegain makes it very useful when paired with the likes of Gourmand's Talent or Trudge Garden to create a bigger army and, of course, more fodder tokens to sacrifice