I guess it’s a matter of taste. Here are some things I do frequently:
In Word, change style. WIth the ribbon, click Home tab, click to open styles, select style. With 2003, click on the styles dropdown from toolbar and pick the style.
In Word, change paragraph spacing. WIth the ribbon, learning curve problem. Click tabs until you discover that Paragraph is on the Home tab. Stare and try different things until you figure out that that little arrow in the bottom right corner of the block will open a submenu, the old familiar Paragraph menu. Iterate a few times until you finally remember this.
In Excel, you want to insert a row. So you go to the Insert tab. No way to insert a row. You finally find another Insert on the Home tab, which turns out to be for inserting worksheets, rows, columns, cells.
In Excel, you want to select a graphical object. In 2003 you click on the arrow cursor icon on the Drawing toolbar then select. In the ribbon, you click on every tab looking for an arrow cursor icon. Not there. Days later, by accident, you happen to discover that in the Home tab, in the Editing block, there is a “Find and Select” button (picture of binoculars), which you never found before because you were using CTRL-F for Find. An item in that submenu has the arrow icon that lets you “select objects.” Try to remember again days later.
In Excel, you want to Insert a Function. In 2003 you select Insert, Function. In the Ribbon, you go to the Insert tab and find everything but functions. After an exhaustive search of every tab, you find Insert Function under the Formula tab.
In Excel, record a macro. In 2003, Tools, Macros, Record. In the ribbon, try the Developer tab, since macros generate code. Nope. Try everything else until you find Macros under the View tab. View? VIEW?!?
Everything I could do in 2003 with one or two clicks from toolbars take at best the same number of clicks and often one additional click in the ribbon.
On the plus side Excel finally has more than a pallette of 40 colors to choose from. Charts look slicker. Conditional formatting is more sophisticated. All desirable but really just bells and whistles.