Originally Posted by
SeattleDavid
Now Fare Class C is required and it is only an upgrade class and is much, much more rarely available.
I agree with this, prior to about 12 months ago I always was able to upgrade using the 15,000 miles and $75. In the last 12 months, I have been able to find availability less than 25% of the time I am looking. I am usually booking mid-con length flights (ORD-West Coast) booked several months in advance.