Instead of just being rants, I found the following pages to be rather helpful.  There are some nice troubleshooting tips, changes you can make to improve performance, etc..

Why Outlook 2007 is slow: Microsoft’s official answer
http://www.itwriting.com/blog/?p=123

Outlook 2007 is slow, RSS broken
http://www.itwriting.com/blog/?p=54

Problem with Outlook 2007 - Email Receive is Broken!
http://www.roundtripsolutions.com/blog/2007/02/19/208/problem-with-outlook-2007-email-receive-is-broken/

What can I do about Outlook's huge PST?
http://ask-leo.com/what_can_i_do_about_outlooks_huge_pst.html