and I recall one January trip when the CUN agent who processed our upgrades (who really had no idea what to do, as a contract check-in agent) returned the certs for me to reuse the following month!

Balanced I guess by repeated delays in obtaining earned certs by mail. Once they were couriered to me and another time Andrew Yu kindly forewarned the local concierge that I was to be upgraded without the delayed certs. But you could book the upgrade hoping the paper cert would be delivered in time. (Don't mention kind colleagues donating them, or worse selling through a TA)

On balance I prefer the ecerts - there you go AC - an IT SUCCESS!!