Maybe the ribbon helps new Office users with discoverability, but for a power user like me, it gets in the way and slows me down. For instance, in order to change the font size of highlighted text in Word, I have to keep coming back to the Home tab, even if most of my current work involves a different tab (such as Page Layout or Review). Another way of viewing this is that the Ribbon forces me to work within and switch between certain modes (Insert, Page Layout, a general mode corresponding to the functions on the Home tab, etc.). These modes don't match my own working modes very well. With a toolbar/menu combination, I wasn't forced into these modes as much. Common processes, the ones currently placed in the Home tab, were always right there on the toolbar, and I didn't need to switch back and forth to use them.