With the reference 'Wenger' benchmark scene: On a 1.3Ghz Athlon running Win2K: Bryce4 - 212 seconds Bryce5 - 239 seconds Difference: 27 seconds - - - - - > Bryce5 over twelve percent slower. On a 700Mhz PIII running Win98SE: Bryce4 - 500 seconds Bryce5 - 546 seconds Difference: 46 seconds - - - - - > Bryce5 over nine percent slower. I consider approximately ten percent slower render times to be significant, and a serious disincentive (for me) to purchase the new release. Compared to the seven to eight percent faster times reported for various Bryce4 scenes rendered in Bryce5 on the Mac, I'm afraid it becomes rather more than a storm in a teacup.