My concern isn't with terrorists being tortured, but with unconvicted (potentially innocent) suspects being tortured. Sacrificing due process has been the greatest cost associated with Gitmo and the whole "unlawful combatants" nonsense.
But there is "due" process....they aren't just grabbed up and shipped to gitmo...there is an interrogation and interview process on the guys sent there...and from the number of these guys who have been released and gone back to killing people, the process is pretty accurate...
It's a limited form of process, with no public scrutiny or oversight. If we have good reason to believe these people are terrorists, try them and convict them and torture them to death if that's your pleasure. But until then, they are potentially innocent and should be treated as such.