Hi Stephen,
I believe it displays a competence with the product, but the main reason for me to study for and take the exams was to have a focus for training and cover parts of the product I may not have touched before. MOSS is a big product and some projects only cover certain parts of the MOSS pie, so having focus for training helps fill in the blanks.
Thanks
Dave
My SharePoint Blog www.davehunter.co.uk/blog