It doesn't really matter what aspect you're talking about. Whether brute strength, speed, mental domination, or magic, Black Courts beat all others hands down.
I don't have something quoting a direct comparison, but here's a segment from It's My Birthday, Too, one of the side stories.
What is it?” slurred one of them. His voice was ragged but not the horrible parody Drulinda’s was.
Her hand blurred, its movement too fast to see. The newborn vampire reacted with inhuman speed, but not nearly enough of it, and the blow threw him from his feet to land on the floor, shattered teeth scattering out from him like coins from a dropped purse. “You can talk,” Drulinda rasped, “when I say you can talk.
From the same story, comparing his brother Thomas to these things:
My brother could go toe-to-toe with a vampire of the Black Court, if he had to, but the last time he’d done it, the effort had nearly killed both him and the woman he’d had to feed from in order to recover
So a White can ramp up to the power level of a Black, but it's more or less open season for their Hunger at that point. It's also noted later that Thomas can only match the flunky Black Court - when he goes toe to toe with a master Vampire that can raise it's own children, he's completely defensive from second one, and he manages to last less than a minute.
The caveat to this is that as long as you can sucker punch them with one of their weaknesses, they go down pretty easy.