Go with the opterons if thats a single xeon. Don't compare clock speeds between AMD and intel directly. They are not fair comparisons. The AMD at a lower clock speed perform on par with much higher clock speed intels.
Go with the Opterons, they out perform Xeons anyway
i agree....this is another reason i'm going opteron....i have a bunch of opteron servers and xeon servers, and although i have not made any side by side comparisons, the opteron seems to perform better (or i might just be biased lol)