If you've only seen one Carmen in pairs then you missed out on Gordeeva/Grinkov's Carmen which is really great.Oddly, I've only seen one Carmen in Pairs:
Canadians from 88: http://youtu.be/6nJ2-U0D4Ck (the male, Lyndon Johnston, actually invented the Natalia spin, made famous by Michkoutienok and Dmitriev)
I think Carmen definitely lends itself more to dance, because of the definitive roles. I like the fact that V/M are trying this music, because they won't necessarily have to play two lovers. Carmen is full of "person a loves person b, but person b loves person c who could care less" (Micaela loves Jose, who loves Carmen, who loves Escamillo, who loves himself).