The answer to this question is a subjective answer that ultimately depends on an individual reader's opinion. Personally, I feel that organ donation is a great thing. It is why I am an organ donor. I haven't donated, but if I die, and my organs can be used to save someone's life, then that's awesome. If my life could be saved because my brother is willing to donate a kidney for me, that is also amazing and acceptable. The key to these situations is that the donor is dead before a decision to harvest organs is made or the person willingly donates an organ that he/she can survive without. This is not the situation in Unwind. Teenagers that are unwound do not have the choice to be an Unwind. An adult orders the child to be unwound, and the child is killed for no other reason than to harvest those organs. The society in the book has bought into the lie that an Unwind doesn't truly die. They live on in multiple persons. That's ridiculous. I would most definitely not want the body part of an Unwind, because I know that having the body part means that a child was murdered to obtain the body part.

Of course I can say all of that now. My life isn't currently at risk. I might have a different opinion if the choice was "have the heart from an Unwind or die." I wouldn't necessarily be happy about how I got the organ, but the will to survive is a powerful motivator, and I would likely figure out a way to justify that decision. If not, the guilt would be awful to live with.