I have never been treated as "less" either by my Master or any other dom I have met. If anything intellectually I have been valued equally or even superiorly, and if we are talking "play" I have been treated "differently", that doesn't mean worse. I get pleasure from submitting, he gets pleasure dominating, isn't that equal exchange? I fulfill the need in him, just as he fulfills the one in me. I think its important to grasp that while we are all born with equal rights, we are not all born the same.
I asked him once why don't I get to spank him? He said, with a half-smile smirk on his face, that I am welcome to try. Lol. That was the extent of that exchange because I simply don't have that intangible quality in me to dominate others by sheer force of my personality. Or at least I have less of it than Him; we are all selectively submissive.
The whole universe, the very essence of life, is based on yin and yang. Every relationship is a power exchange. Granted not everyone is into "pain" aspect or bdsm related fetish, but every marriage or romantic coupling is D/s, its give and take, and its never that unattainable modern myth of absolute 50:50 equality all the time. I can take the spanking, but I couldn't take "the silent treatment", to me thats unbearable cruelty. And what is silent treatment if not (gutless, imo) D/s power tripin'?
And the analogy prisoner-sub just doesn't stand, prisoner is there against his will, sub choses to be there, she asks to be in that position and is free to leave at any time. For me, being forbidden to express this part of myself would equal prison.