*I'm not a fan of early mornings, I did post in this thread previous, I actually did want to modify my previous post because I had more to add onto it, but in my tired state I hit the remove button instead and now find myself having to retype it, I'll try to mimic what I wrote previous while adding in something more to it.*
As I said previously, for me it does come down to what the particular person perceives as perfect for them, every s/s does have a general idea of their ideal D/M, just as most D/M have an idea for a perfect slave. That being said some D/M do love mouthy slaves, others aren't too fond of them. Some like the passion and intensity that subs can bring to things, some D/M enjoy 'breaking them in' because it adds to the challenge of things and can make things interesting. On the opposite side of the coin, many find a 'living doll' idea to be ideal to them, but some others find that far too boring, and in all honesty, I am not a D/M by any means, but I can see how that become repetitive and boring to some people. All goes by taste, and that's all part of the 'hunt', if you will, very much like any relationship, you find the ideal person for you the one that works for you.
When it comes down to 50/50 relationships, it is true, there is no such thing as them, one person has to take control of the situation, there has to be a leader, there has to be one Captain to a relation, can't have two people running one ship. In that sense there is always a leader in the relationship. With that in mind, different people show talents in different things, some are better talkers, some are better at fixing things, does the situation switch around? No. But it shows what each person is good at and allows the person who is the leader in the relationship to decide what should be done and the best time to do it. In the case of fixing something, you'll often find a wife, for instance, mentioning that something has to be fixed, in this case the husband will be the one to fix it, and usually he'll find himself down so, in that sense the wife is in control, she is making the order to fix something, definitely not the best of examples, but in terms of the Captain/Crew, the Captain tells someone when something must be down, and the Crew goes and does it. So in that sense, every relationship needs a Captain, it needs a leader, and even if two people say they are 50/50, more than likely one of them is in control, it's just that neither of them have fully noticed it. This does often lead to fights, these fights usually dealing with a sort of 'power-struggle' with both sides jocking for control over the 'power' in question. In this case, it is the leader that wins, or in some manner, let's the 'Crew' believe that have won something, but only because the leader allowed them to do so.
That being said, my outlook on it, is like down, but when it comes to the actual practice and terms? Well, let's see...
slave - This one I feel can sort of be willing and unwilling at the same time. It can be either or both. In my general opinion and slave is more of a position more for the 'living doll' types, there purpose is basically that of one. Willingly, the position is brought down to more of those that are willing to give up there lives to a person, not just small little kinks, but just about everything, mind, body, soul, the whole being, handing over complete control to their owners. In the opposite outlook, this can be unwilling in that same way, because a slave can be viewed as an unwilling participant, but I person believe that it can go both ways, it's just the general outlook on it. In both cases however, willingly or unwillingly, the slave is required to do whatever is asked without question, they have no life, outside of their owners life.
submissive - I find the that is sort of the happy medium of things, that the submissive does hold some control over what is happening to them, more along on what they like, and what they dislike, in terms that the relationship her is more open, with the D/s, talking about there kinks beforehand, setting out some ground-rules and working on from there. This applies more as a relationship than M/s to me, in terms that unlike with the M/s situation, you'll find yourself looking for someone that isn't a total 'living doll' and that has a mind of her own. Unlike the slave, the submissive has more of a mind that she can use, she has a little more 'control' over her situation, but in this case is willingly giving herself to a Dominate, but doesn't maintain to being just a doll, she has a life, at least more of one than the slave.
bottom - With the T/b look at things, the bottom, has just as much if not even more control over the situation in terms of the allowance to use a safe word to stop a certain situation, the safe word is often set-up earlier in time, and usually, as far I as I could usually see it to be, terms aren't set up before hand, things just gone onward until the word is said, so in this case, it comes down more towards trust and communication than with D/s. You have to trust that your partner will not go too far, while also trusting your partner that they will speak the safe-word when needed to. Unlike above she has complete control over her life.