in Finder list view (i searched and didn't see this, so if it's a repeat i apologize...), turn OFF "Show File Sizes" for the Global List View. As all Cocoa applications are now packages, meaning they're actually directories, this is the same as turning off "Calculate file sizes" in the OLD finder and foregoing the minutes it would take to go through each folder, calculate the size, then go to the next folder, calculate THAT size, etc etc. It's equally slower (if not slower) in X.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010524024555603