I am not primarily interested in utilitarian arguments about torture. My arguments on the subject have tended to be moral and legal. And, I do not believe that either would be altered by the discovery that torture was an effective means of interrogating prisoners.
Nevertheless, there are a lot of well-intentioned utilitarians out there, and some may be concerned that were it to stop torturing its prisoners the CIA might somehow miss out on a valuable interrogation technique. Well, rest easy: The current issue of The Atlantic has an article by Stephen Budiansky that eloquently confirms that being nice is a much more effective means of Truth Extraction. But we knew that.