It clearly showed that torture softened him up. When they were doing the traditional interrogation right after they tortured him, he figured out that they were lying to him (about giving up information during the torture sessions) and started to not answer, but they threatened him "do you want to get tortured again?" The answer was no and he started to comply.
The film dramatized the torture but was still excellent overall. The CIA was more systematic and clinical with their torture. They would always ask the subjects control questions, and those that didn't comply would be tortured until they induced a state of compliance. Then they would start asking for the real information with traditional techniques. The name for bin Ladin's courier really did come out of one of the people who was tortured.
Being systematic and clinical are crucial to the efficacy of torture. If you are just trying to pin something on someone, and want to torture someone for the answer you want to hear, it'll end in disaster. We sent an Al-Qaeda leader to Egypt to be tortured more harshly and that was where the "Saddam is linked with al-qaeda and is helping to get WMD's for them" justification came from. I don't think you can blame the tactic of torture, in and of itself, for this failure, rather I'd blame the desire that existed to pin something on Saddam and the inappropriate application of the tactic.
What a barbaric, inhuman, and unconscionable post. Disgusting. To think that we can so dehumanize torture into being "systematic and clinical" ... that such robotic efficiency is what justifies and validates the act.
Then again, this is from someone posting the defense of a character who executed children, so ...