After perusing FlyerTalk for AA promos, and looking at DL vs. AA award availability, I have literally canceled my next ten (yes, ten as in one-zero) stays with Marriott (they were already booked), and have given them to Hyatt, specifically because AA and UA miles are more useful than DL miles.

I will be saving the folios and faxing them to both the Marriott Rewards Platinum desk, and to Mr. Marriott's office. Even the devaluation last year did not drive me away. This has actually made me look elsewhere, cancel reservations, and book with a competitor.