Simon,
Thank you for that info. I suspected that it would work this way as well.
I believe the I would only need a "Before" condition if in fact I want to limit the response to only those documents that actually had a certain value prior to the change.
For example; A BEFORE status of 'Removed from workflow' and an AFTER status of 'New Document' would trigger if I specify that BEFORE status value. Whereas changing the Status to 'New Document' from 'Processed' would not trigger as I have not specified that value as a BEFORE condition.
Is my assumption correct?