Two different occasions:
1. Two free night cert with a suite upgrade stacked at the Grand delMar. Amazing property. Search this forum for my review. Basically, $3000 stay for free, but I spent $2500 on property.
2. Fairmont Princess Scottsdale: Upgrade to Gold+Suite for 2 nights. Wonderful experience. Excellent Spa. Awesome Gold Lounge staff.
My next stay will be in Boston with another Gold + Suite upgrade later this month. The Copley Plaza is the Fairmont I know best, having stayed there > 50 times in the past 25 years.