After class yesterday, I realized that a lot of discomfort with Cyteen's universe comes from the fact that individuals' futures, to some degree, seem to be determined by forces outside their power. This outside force appears in the form of tape, genetic manipulation, and environmental manipulation, as with Ari. However, despite this level of control, and despite the disturbing subservience of the azi, the technology of tape and genetic manipulation doesn't really scare me on principle. What scares me in this is the culturally developed belief that behavior is deterministic. It is this belief that presents a society which appears so sinister. The tape is useful, and yields a more competent, but the mentality of control causes simply sad situations, such as Jane leaving, to turn into scary ones. For Nelly, instead of letting the grief of loss reshape her personality, as would happen in our society, they find it necessary to reprogram her to handle the loss, because to do otherwise would be to lose a valuable asset. What is really being done to Nelly isn't really healing at all. It is merely reestablishing the control which the society has over her.
"[T]he technology of tape and genetic manipulation doesn't really scare me on principle." I find this is true with basically any technology. Anything we develop has intrinsic value--meaning it is useful for something--but is not inherently a bad or a good thing. As you point out, the problem comes from the way we then use the technology, and most authors are inclined to go with the idea that it will be used for power/manipulation because humans are naturally competitive and hierarchical (man, that word...), rather than the idea that humans are purely good and will only use technology in the way most beneficial to society. Where the reality lies between the pessimism and the idealism is up to interpretation.
"Most authors are inclined to go with the idea that [technology] will be used for power/manipulation because humans are naturally competitive and hierarchical... rather than the idea that humans are purely good and will only use technology in the way most beneficial to society"
By this argument, what they do in Cyteen (mindwiping, recreating Ari and running the replicate's life) would appear to be the pure noble act of continuing societal progress. To do otherwise would be an entirely selfish act that removes a brilliant and re-obtainable mind from continuing to function and advance technology and society, or a constructed being from further functioning. So really, the question should become how far can societal progress go and infringe upon the rights/moral wellbeing of an individual before it has gone too far?