I prefer a theoretical socioeconomic based affirmative action to a theoretical race-based affirmative action as more of a compromise position.
In truth, I don't support affirmative action at all. If you got a sob story, tell it in the PS or show it in the resume and let that be the only really subjective measures.
I'm much more in favor of efforts to fix a sinking system rather than pretending the leaks don't exist and trying to bail water out when people are 22.
I think the studies you cite are interesting and I'd seen at least one of them before, but they're also superficial and not at all conclusive. You know that.