I use Bryce on pcs and macs because I don't want to tie up my computer with a long render, so I copy the scene file to my other pc or mac. The mac has more memory (1 gb) and its a little faster and quieter, good for those overnight renders. I have been disappointed with Bryce 5.5 because I can't switch stuff from my pc to my mac. Bryce 5.5 should handle the same stuff that 5.01 does. The last time I did that the program would hang on the mac. This is a scene that my pc could handle with no problems. After this, I don't trust Bryce 5.5 on my old projects on the mac. Bryce 5.5 should be backwards compatible and cross platform but its not. Can't go back to 5.01 on the mac because 5.01 does not work on Tiger. Did post the error on Daz's bugtracker and they sent me an email saying the bug was closed. Hopefully 6.0 will be better or I will use Bryce less.