I think the guy's point was related to the fact that the OP said he was told by his dealer that their RAM available now is native 800 AND that they only use micron chips. Surely if micron had native 800 chips available they would sell them on their own crucial site?
No, you can't draw that conclusion -- Crucial has to build and test the modules before they will advertise them, it's not merely a matter of supply of the 800 MHz components. 4 days is not a long time, so don't read any extra into the fact that their MacPro finished module is not yet advertised.
Could it be true? Of course it could.... and Ross Perot could re-enter the Presidential race with Ralph Nader as VP and win it all... Is it likely to be? A salesman reporting a rumor they heard, with admittedly no evidence? You be the judge of that. The point is, even if there is a difference, both designs will be well within bounds of Apple's thermal guidelines - as will all other reputable brands.Can this be true? He said for me not to "quote" him as it was not an official OWC statement and because it was a recent rumor and he had no supporting evidence yet.