http://www.blairwing.com/images/ULTCo2/9.jpg
I found this while looking around online. This seems relevant to the discussion. From what I've seen, and read certain heatpipe heatsink bases are overly thin. Sometimes to the point of base warping under high mounting pressure. So you need a thick enough base to keep from warping, yet focused cooling all across the die. The hottest die spots are not in the center of most cpu dies, but off on the side halfway between center and the corners.
I got a birthday notice in my email, and remembered I had an account here
Sooo I'll be more active.