Appearing on the Xbench comparison site yesterday, the Mac Mini (1.42GHz, the US$599 model) results. I did a quick comparison of that to the iMac G5 and found it to be about 2/3 of the speed (overall) (not surprising given that was a 1.8GHz G5). Comparing it to the iMac 17" 1.25GHz, it comes out a slight winner, and compared to the top-of-the-line iBook it is about the same. Graphics performance is a little bit lower under Quartz and higher under OpenGL.