On one level, given a choice between compelling obedience, and compelling obedience AND inflicting suffering, one would have to say that compelling obedience without suffering would be less unethical. This, I suppose, is the basic difference between "Brave New World" and "1984". Stated differently: if there's an unpleasant task that *must* be done, one could justify utilizing an agent which will experience less discomfort during the task -- the question becomes how then to ascertain "necessity".

A being that had a human(-like?) body but a circumscribed consciousness is, in my view, not properly "human". I would draw a distinction between reducing a pre-existing human to such a state (such as via brainwashing), and growing such a being from scratch -- the former being more troubling than the latter... For me, this has something to do with the "potential" of a given being versus how it's allowed to express. The domestic dog, for instance, comes both in breeds that nobly adapt its wolf origins (such as herding dogs) as well as breeds that subvert that origin for what I call frivolous aesthetic reasons. All that being said, it could also be less immoral to keep a species around in acceptable form than to cause its extinction with its charateristics intact.