Just out of interest - and I'm not having a go but I don't understand this - can the people who think the 40k-point free night certificate is of limited (or no) value explain their stay patterns for the other 74 nights of the year required to get the free night. Clearly, everyone has different stay patterns and expectations but I can see a cold hard US$250-450 cash saving from the free night. There are numerous quite acceptable Category 5 hotels in, say, HK where the rate can regularly be US$250 a night (Marriott Ocean Park) and at peak times go up to more than US$450 a night (Sheraton Macau over New Year). HK hotels are on the expensive side so equivalents must be available in major cities elsewhere.
It's not like the free night is forcing you into an obscure Four Points, Courtyard or Moxy at ~US$100 a night. I just always find it curious when people say it has limited or no value to them and am probably envious of people who exclusively spend 75+ nights a year in St Regis, RC or W hotels in tier one cities.