In the Finder, the PowerPC's power is seen in the Finder's new multithreading capabilities. In essence, this feature allows users to make multiple copies at once and in the background while working on more important things. You can launch apps and empty the trash at the same time and so forth. Copies themselves are enhanced, by the way. You now can get more information on the files your copying as well as an estimate on when the procedure should be finished.
Copies are also substantially faster as well.
Your Mac's appearance is far more customizable than before, yet, not so much so that third-party opportunities are lost. First, for the first time, we can actually change the system font to whatever we please. Currenty it is a font called Charcoal, a sort of cross between Espy Sans and Chicago. For those of us who would prefer Espy Sans Bold, we can simply open the Appearance Settings control panel and change it. Further, we can also change the color schemes used by the Mac OS to draw progress indicators, scroll boxes, highlight colors, etc.