If I am convinced God does not want me to do something, especially if I have received a personal answer of some kind, I won’t do it – no matter what mortal tells me to do it. I still will “sustain and support” my church leaders in their callings, even if I can’t do exactly what I’m asked or counseled to do, but that wording does not say “obey regardless”.
D&C 121 is crystal clear about demanding obedience simply because of one’s position of authority, “as they suppose” – and I’ve never believed we will be blessed for knowingly doing wrong. I just can’t accept that we will be blessed for sinning, and since “sin” generally is defined partially as “knowing right and doing wrong” – I don’t buy the argument that we should obey any leader unquestioningly if they tell us to do something we believe to be wrong.
Having said that, I’ve thought and prayed about counsel I’ve been given with which I disagreed, and I’ve changed my mind as a result more than once. I also have accepted and followed counsel I believed to be poor counsel but not morally wrong in many instances when I have offered my own counsel and the leader reached a different conclusion. That’s just life in a community / organization of any kind.
I don’t believe in reflexive dismissal, and I agree totally with Elder Oaks’ characterization in his talk during General Conference last year in which he said that reflexive disregard for commandments and counsel due to a feeling that one is an exception to rules does not originate from God. At the very least, I would say such disregard is born of pride.