I upgraded from Microsoft Office 2002 to 2010, because (1) I got the upgrade at a fantastically good price; and more importantly (2) my son, who knows more about Excel than anybody I have ever met convinced me that the new Ribbon Interface and logical structuring of the user interface was greatly superior to the old. I trusted his judgment and upgraded... and hated the ribbon interface. Until, that is, I had spent about six hours with it and understood it, and (as he promised) I would never, ever consider changing back.