Okay, what the hell kind of "intelligence"

do you get from people who have been locked up in a secret location, with no access to a lawyer (or anyone else for that matter) for 6 years?

US admiral confirms secret camp at Gitmo

I have some guesses. You wouldn't get any kind of relevant military intelligence, but you might well get a lot of psychological intelligence, as in these guys are being used as human guinea pigs for God knows what awful kind of purpose.

Here's a year-old article by Naomi Klein that speaks of what I mean:

The US psychological torture system is finally on trial

Note: since then, Jose Padilla was sentenced to 17 years in prison on charges different from the ones he was actually imprisoned and tortured for.