This article is incorrect.
I have windows 7 pro 64 bit, and outlook 2010.
The pst files and roamcache, are in fact stored in
C:\Users\yourname\AppData\Local\Microsoft\Outlook
In "Outlook Files in your "Documents" folder is just an empty unused pst file.
I use imap and exchange. Im guessing that the Documents directory is only used for the ancient pop3.
I tried moving the pst files from the Appdata location, but outlook simply creates new ones in its place, and then gives errors when you try and open any mail.
I had to delete every account and start again.
I have spent 2 weeks trying to find a way to move outlook data files - it does not seem possible with my version of outlook 2010 at least.