I saw the comeback offer during my Feb trip this year. It was a very good rate. It was just 2 or 3 dollars more per night (moderates) than I had booked with the AP rate. You had to call from on property before your stay ended to book with that rate.
The only thing I didn't like about the offer was that it was a "package" through WDTC. It required a $200 deposit and the more strict cancellation and payment rules of WDTC.
Of course, if I hadn't had the AP rates available to me, I would have done quite a little dance for joy even with the added restrictions.
I didn't see that offer when I went back in May, so I'm not sure when they ended that promotion.