Wanted to SDC on a mileage ticket to a flight 2 hrs later, but the low award level for the later flight wasn't available. After 3 HUCA attempts I gave up. Turns out my original flight was oversold so at the airport they moved me to the later flight I wanted originally (except that I couldn't spend the extra 2 hrs with family as I had hoped). I got home 5 mins earlier and with $750 into pocket.

The truth is, though, that I'd rather DL had just let me SDC, and they could have kept the $750 and I could've had the extra time.

The practical truth is that, especially on award tix booked in advance at lower levels, SDC is no longer possible. So what's the point?