Aye, I've only used OSX a few time, but having benchmarked nearly every combination under the sun, I have come to this conclusion : Bryce rendering on a dual G4 or G5 setup is still slower than a really cheap Athlon setup. So, if speed is the issue, it's not BRYCE that would hold you back, it would be the inferior hardware. Upgrade to an Athlon, and you'll be fine. The price of a good Athlon setup is still merely a fraction of what it would cost to buy a MAC. But, you've already bought a MAC! And now you are wondering wehter Bryce is worth 60 bucks? Your computer is overpriced by thousands of dollars and you're worried about wether a 60 dollar product is worth it? Sounds kinda silly, to me. Go sell your MAC, and but three or four brand new, much faster Athlon setups. Network render it, if you want speed. A MAC user complaining about speed is preposterous to me, if you were interested in speed then you wouldn't have purchased a MAC in the first place, you were only worried about ease-of-use. The only people that still believe MACS are faster are the people who are ashamed of how much money they spent for no reason.