On the Yahoo-groups Bryce list, there has been some discussion about a difference in render speeds in Bryce5 between Macs and PCs. Over there, Dan Whiteside reported the summary of his investigations: "...I finally got my release copy and loaded it up on my side by side Mac/PC setup at work. After seeing the benchmark results, I wasn't at all surprised when a couple of different PCB5 scenes came up about 4-5% slower then PC B4 while the Mac turned out to by 7-8% faster. Interestingly, all the render reports (PC B4/5 and Mac B4/5) showed the same Ray hit/miss results." I read from Dan's words that for the same scene, Bryce5 is faster than Bryce4 on a Mac, and Bryce5 is slower than Bryce4 on a PC. The logical conclusion is either that Bryce5 is optimised to run on the Mac platform, or that something is different about the way default render settings are configured in Bryce between the two platforms. Given that the ray hit/miss results are the same across platforms (which implies the render settings are the same), I'd have to lean toward the notion that Bryce5 is straight out optimised for the Mac. That's enough to stop me buying it. I was going to order it this weekend, but shall now wait until more information is forthcoming about this issue.