I'm thinking of getting a new Mac Pro and my primary application is Aperture (and NIK). What matters when it comes to Aperture performance? On my current 2009 Mac Pro it seems to run reasonably well. The slowest parts of the workflow are import (likely due to my CF card/reader), post-import processing (is that CPU or GPU?), and switching from one RAW to the next (waiting a few seconds for it to render - again is that CPU or GPU?). As for exporting, I only publish to Zenfolio or Facebook so internet speed is the biggest factor there I believe. Any thoughts?