In best-of-one, your sideboard is limited to 7 cards, while in best-of-three, your sideboard expands to 15
On the flip side, the Dual Standard format was clunky at times, and Im still not convinced that WotC has figured out the best way to hold and present events like this yet
Denethor, Ruling Steward's first ability will trigger only once during your end step, no matter how many creatures died under your control this turn
Because of Derevis unique ability to just place it on the battlefield from the Command Zone, you can repeatedly use Derevi as a sacrifice for your Pod-like cards, starting at four mana and going up from there
If you want in-depth tutorials on how to play a particular deck, there are dedicated strategists on YouTube that will show you how its done