Yes, that's pretty much my sentiment on Arkin as well. I strongly disagree with his politics (and I'm sure I'm reading his book for very different reasons than he intended in writing it), but he's good at digging up this type of information. Apparently he heard about Harmony from somewhere or someone, and what he says about it is consistent with what Patterson says. I'm wondering now if any other information about the program has leaked out prior to this, perhaps without reference to the program's name.
I've been told off record by some people that there are some important revelations in there concerning Saddam and terrorism but I don't know if anyone else has really gone on record about it. Would be interesting to see.