Merger Postive: Breezeway
One thing DL seems to have fixed from the NW side of things is priority boarding. Over the past 5 months or so, I've pretty much always boarded after F/Elite boarding, and every time have been able to walk straight up to the GA on the Breezeway side of the boarding lane, present boarding pass, and proceed. My success with the Red Carpet was not nearly as good.
So +1 for DL there.