I should probably have linked to Sandy Bridge EP vs Bulldozer, which is much more lopsided. The 6C holds its own nearly everywhere, with comparable price and much lower power usage, and there's always the option of bumping up to 8C when needed:

http://www.anandtech.com/show/5553/the-xeon-e52600-dual-sand...

This latest generation was not favourable for AMD. 16 core Interlagos in many cases barely outperforms the old 12 core Magny Cours.