AMD Opteron

After someone posted something on our forums about AMD Opteron processors I googled them.  I went on the ADK website and saw that many of their famous "clients" are using them and not the Intel 980x.  From my understanding, based on these forums and Scotts benchmarks I thought Intel was the top of the line for audio, specifically the new 6 core 980X.  I would of guess the only thing better would be a duel 980x set up.
 
I had not previously heard of the AMD Opteron series and it looks like AMD is coming out with a Bulldozer series next year.  I was planning on going with the 6 core 980x for my next build but it appears as though I am clearly missing something.  Anyone have insight on the AMD Opteron builds and why they are so popular?  Do they outperform in a duel processor configuration that the Intel?
 
-Mike

Thanks for the info Scott, apparently I was in the loop after all.  There is a first for everything I suppose. 

While we are talking about systems, I understand there was some latency introduced in the old Xeon setups, is this still the case?

I am considering the slave route with my next set up, didnt know which was more cost/perfomance effective.  I still have maybe another year or so until I 'have' to decide so I will see what technology is out then.  With the release of Hollywood Strings and Hollywood Brass soon I am hoping for better 'single CPU' perfomance technologies with large orchestral templates.  Maybe in the next year Intel will have a 12 core I7!