DL phone supervisor just told me this yesterday. I had booked a Decemer AF trip in "A" class to use SWU's for "O," but the rules changed an prohibit using "A" for swus and the selling agent didn't know. Supervisor switched me to DL metal and confirmed Z.
The supervisor promised a "comparable" experience in J on DL's 763 vs AF 330. Except, of course, that the return flight lands one hour later.
Thoughts? I've only seen DL's domestic 763 fleet and never flown AF.