doing excellent 3d renders requires years of experience and an huge catalog of files IMVHO.
 new poser users can't do excellent renders, because they use defaults:

• no shadows (bad lite settings)
• no clothes
• no facial expressions
• no props
• stiff poses
• empty scenes
• bad AO/IDL settings
• bad render settings

whether OS X or vista don't matter, altho mac users can run windows (intel) files using
crossover.app.  I would not waste money on parallels, as crossover don't need a vista
install on OS X machine.  I found the parallels ad started to reappear above, even tho I've got
flash ads blocked, because it's run by a java app.  disabling browser java (not included in
new html5 standard) cures that problem right quick.  of course, html5 devices already have
java and flash disabled.