I haven't gone with 32 bit, I installed 64 bit. Of course I cannot say what difference in performance there is but I can say how surprised I was to find that all my apps run perfectly; even Need for Speed 2000! The only slight problem was with Quickbooks 2004 and the problem, is only that it can't seal with the email options.
Right, I'm waiting to be told I am all wrong and should have used the 32 bit version but as I don't have any problems here I don't think I'll worry to much.