I reserved four nights at the Fairmount Kea Lani using free nights from the credit card. The Fairmont program definitely has some interesting rules.
First, they mailed me physical certificates which I will need to bring with me and present at check-in. They could see that I have free nights earned on my account, so I don't know why I actually have to present the certificate.
Second, they told me the room rate for each night of my stay was $700, and that if I fail to cancel the free night reservation 21 days in advance of the free night, I will have to pay a one-night charge ($700). I know SPG has similar rules about a cash charge for no-shows on award stays, but this seems excessive at 21 days. Oh, yeah, if I accidentally forget to bring the certificate on my vacation (or lose it), I'm out of luck and will need to be pay the $700 for the first night if its within 21 days.