I had a worthwhile 2-night stay this weekend at dulles . Used my Amex membership rewards cert of $100 off two nights, which had cost $15 in Amex points. This required use of the daily rate of $79/night. Used a Costco cert, and the remainder was only $13. Stayed sat/sun , got the g2 bonus. Total cost of $68 got me 2 nights closer to diamond and the decent amount of points.
Sunday is usually more expensive but with the holiday they used weekend pricing. I have one more of these Amex certs but will likely have to use it in a non-bonus point weekend stay