What Does Marvel Rivals Do Better Than Overwatch?

Now that the game has been out for a while, I want to hear some opinions from ex/current Overwatch and Rivals players.

What aspects of game and hero design do you like about Rivals over Overwatch, and conversely what does Overwatch do better than Rivals?

Also, for ex-Overwatch players, if you could pinpoint something that killed the game for you, what would it be?