I bought the upgrade a couple of weeks ago and have not used all the features yet and found this review at maccentral:
http://www.macworld.com/2005/09/revi...ysx3/index.php
SO COOL!
I set the hot key for it to be f1 then I assigned one of my many mouse buttons to F1.
Its like a expose for your favorite quickkeys.
I just made myself even more productive.