For those who got your certificate extended, what type of certificate was it? The Marriott premier credit card annual CAT5 certificate, or the Megabonus CAT4 certificates? I heard it's easy to get the CAT5 extended, but not the CAT4.
I requested an extension for my CAT4 last year, but MR denied it. Fortunately, the hotel I was going to stay happily accepted my certificate after its expiration date. (Technically, I booked the stay before the expiration date, but had to push it back a week past the expiration date. The hotel changed the date of my reservation and took the certificate)