I'm not sure what the qualification requirements are for CX DM, but perhaps the new QF platinum 1 status is as hard to acquire (essentially 3x the basic emerald requirement, with over 2/3's of that required to be on QF metal).
IMO, the best benefit is that any revenue seat (QF metal) will be made available for award redemption at basic award redemption rates. Some freebies and other benefits as well.
cheers