https://www.hiltonselect.com/enroll_options.php
I actually got offered a discount taking the first option to $259.
The benefits here on the cashback for stays look pretty "meh" (mail in folios, aka "lots of breakage and opportunities for shenanigans").
https://www.hiltonselect.com/enroll.php
I'm inclined to think "no, put it in the trash bin", but wondering if anyone else thinks differently.