The SA Forums model does accomplish the goals of filtering out noise, but then you’re stuck with a stagnant community of “the right people.”
Everything else seems to eventually cause new blood to dry up.
And about the same frequency you’d be assigned to metamoderate, basically being asked if a moderator’s “vote” was a good one or not (you didn’t have to fully agree you’d do the same, just that it wasn’t bad).
Someone who scored low in meta moderation would get less or no moderator chances.