A lot of things about Matt Simmons bother me. While I'm not a big fan of "conspiracy" theories, he is a member of the CFR (like Judith Miller). I think one should always be careful about sleeping with your enemy's enemy.
I'm glad to learn that I'm not the only poster on theoildrum who has misgingings about Matt Simmons.  I tried to raise these concerns on the open thread of Oct. 19, but the responses were uniformly replete with praise for Simmons (not that this praise is undeserved, but neither do they adequately quell all the misgivings):

http://www.theoildrum.com/story/2005/10/19/23321/213#comments