I\'m runnin\' on a 600 G3, 256 megs of RAM. Honestly, I have heard quite a few complaints about speed but I don\'t seem to suffer from any problems so far. The only time I notice any problems is when I have LimeWire (A java program aka memory hog) and I\'m messin\' with the Dock. But that is due to LimeWire and not OS X.
With that said, I still plan on throwing a 512 Meg chip in next week .
You used Audion 3 yet , No One? It\'s a great MP3 player. Only thing is its limited to 15 days and after that it shuts down every 30 mintues. I may go ahead and buy the full thing for thirty bucks.