I thought that these two articles are interesting additions to this debate.
http://blogs.zdnet.com/Bott/?p=369
http://blogs.zdnet.com/hardware/?p=1332
And this explains a lot about Vista performance as well, if you have the
time.
http://channel9.msdn.com/showpost.aspx?postid=242429
Maybe some of our MVPs know or know of this gent. He offers a very coherent
discussion that touches on RAM, Superfetch, defragging, that even a
non-techie like me can fairly well follow.