Once you embark on a DD FLR, is 'equality' an obsolete notion? Granted a BDSM M/s or TPE, and even D/s relationships are based on intentional inequality. Is DD different? Many would say it is, but I'm not so sure. Granted there might be more sharing and negotiating in a DD arrangement than a more extreme relationship, but doesn't the mere fact that one party has disciplinary authority over the other substantially tip the scales?
The thing about equality is that it is a quantitative absolute. If you have two equal things in balance, you need only add one grain of sand to one side to tip the scales. I suppose once one embraces the inequality, then everyone can argue or evaluate the degree of the inequality. That I can understand better than maintaining the notion of egalitarianism by virtue of qualifying the balance by saying, "well we just have different roles, but they balance each other out." That just seems like a rationalization for someone reluctant to accept inequality as a valid option.