The broader target range and better late game scaling make Oust the better control card but both are good enough that you will play either in either if you just need more removal
They are not unlike pump effects in aggro decks
Repulse: needed, but much more costly than it's better cousin Void Snare
Flying, unblockable, fear, menace, all these evasion abilities help to make you more likely to gain a card from combat damage
Of course, there is no shortage of such decks, with Animar, Soul of Elements, Halana and Alena, Partners, and the new Chishiro, the Shattered Blade all being quite good choices for a red commander that benefits from +1/+1 counters
You even get a sneaky infinite combo with Peregrine Drake, Archaeomancer, and Ghostly Flicker