Sabers could run it. They only Special Summon when they go for huge plays, and Duality actually sets up big plays by choosing backrow hate or the necessary combo part required so that they can go for the kill next turn.
Frog Monarchs can actually run Duality thanks to Gorz/Battle Fader/Tragoedia meaning that the "no SS clause" is laughable. But a high monster count can put this idea out of the window.
In general, the "no SS clause" is laughable when you put huge pressure on the opponent.
Also, being able to choose which out of the top 3 cards you want is huge. And Duality has no huge drawbacks like Reckless Greed and Upstart Goblin in the fact that you're not giving your opponent something in return for the card you draw.
However, what I have said is not intended to be intepreted as "Use in everything", because sometimes there just isn't space, or its drawbacks conflict with the deck it is being used in. Take Gladiator Beasts for example. Outside of the first turn, you really don't want to draw into Duality as you need those Special Summons to get you advantage. It's also risky with Lightsworn since you can't SS any milled Wulfs.
I'd say that Duality is a near-splashable draw card.
Standard Beatdown is a bit vague IMO.