Canada

Fair point. It also highlights why I consistently will use any other words than upper and lower (though I don't think I've consciously acknowledged or analyzed that before). I never really had a reaction to middle because it is largely defined in terms of relationship to those between which it sits anyway. But upper and lower carry so little information about the power dynamic as to be deliberately vague.

And while I don't think "class" as a designation of social status is really meant to imply no hierarchy of power, it certainly does downplay and obscure the underlying mechanism. I think the reason I like keeping it is that it ties the social hierarchies people recognize (and with "capital" the economic system they at least acknowledge) to the actual mechanisms giving one control over the other.