Actually, you've pretty much won this argument.
As I'm working through this, I've been finding enough information this week (particularly today) to convince me that the negatives of extreme interrogation on balance outweigh the positives (see also some other threads where I'm discussing this). I'm still not sure about the usefulness of conventional interrogation in a "ticking bomb" situation--most of the successful terrorist interrogations I've seen involve getting information on things the terrorists have already done.
But you can take that as a win, if you want.
Still, I expect that this stand will someday cost some innocent lives. That's one of the negatives on the other side. I hope those currently making a major issue of this will remember that then.