Apple's Mac Pro has design innovations that we hope will cross over to other systems. Its performance is as strong as you'd expect for a system in its class, and it's priced right, too. You might need more flexibility in your config options, especially for 3D design, but otherwise, the Mac Pro is as solid a professional-class PC as we've seen.
Windows Vista has been in consumers' hands for about a week now and, while there haven't been a flood of problems, there have been a few bumps along the way.