"Canon Professional Services (CPS) provides exceptional benefits for individual full-time imaging professionals. CPS members receive exclusive phone and e-mail support, expedited and discounted services and repairs, equipment evaluation loans, service loans, on-site support at select events and shows, plus discounts on Canon Live Learning workshops, and more"
Assuming you use the equipment every day, and have several bodies and many lenses, the $500 is nothing compared to the savings in turn around time, repair costs, and the use of a loaner if a repair cannot be quickly completed.
If you are not using your equipment daily, or only have one or two bodies, I'd use the gold level.