My opinion is just this:
1) Human rights are human rights. You either respect them in all cases or recognize that they are a sham. Not respecting them proves our enemies right about us: we don't really believe in the moral principles we espouse, we just claim to in order to justify our imperialism. It also reduces our capacity to lobby other countries to do better in the field of human rights, by destroying our moral credibility. Human rights abuses in China are harder to get outraged about when we don't respect rights either. And it doesn't matter that they violate them much much more: rights are not a matter of degrees. They either exist or they don't.
2) Torture doesn't work. People will say anything. These people don't have current information. Terrorist organizations are cell-based so these people didn't know anything to begin with. They are likely to lie just to get the pain to stop. That causes us to divert resources to cover non-existent threats, increasing the likelihood of a successful attack in a different place.
3) Torture and abuse cause outrage in the Muslim world, leading to a greater proclivity to join and endorse terrorist groups. Recruitment pamphlets from terrorist organizations recovered during the war have listed abuses at Abu Ghraib and Guantanamo Bay as justifications for violence against the United States.
4) People are not guilty until a court says they are. They are not implicated until they are charged. It is unacceptable to prevent any findings of fact in this matter. The power to suspend all legal rights is not a power the government should ever have in any case. The precedent it sets is terrible.
That, put very, very briefly, is the outline of my argument. Even if you don't agree with the points I make, I'm not sure how you could possibly misunderstand it.