Because multiple sellers compete on the same listings, its often easier to compare prices and find specific cards than at traditional retailers
In short, if you get the landfall trigger in your first main phase, your creatures wont untap for your actual combat phase once the extra combat steps finish
I suppose Im the most skeptical of the blue ones with their best cards historically being things like Snapcaster Mage and Cryptic Command, blue decks are hungry for more mana, not more cards but Sunbaked Canyon seems like a major upgrade for Boros Burn, and its easy to imagine previous Golgari and Orzhov decks that would have loved an in-color Horizon Canopy
Kiki-Jiki can copy Felidar Guardian, which will, in turn, flicker your Kiki-Jiki
Austere Command Generic Board Wipe Look, Austere Command is not a terrible card by any means