First off I'd like to say a big thanks for putting together such a well thought out and thorough optimization guide. I tried writing one myself, but I found it was easier, and often yielded better results to just send people in the direction of this thread.
After reading the discussion here about what effect memory bandwidth has on the performance of the game, I did some testing on my own, and here are the results:
Memory bandwidth; should you be concerned?. I just thought it might be of interest. You also have my full permission to include it in your guide in whichever way you wish, if you so desire.
/Nalv