Well... one area AS shines in F compared to Delta (and maybe the only?) is wine quality. AS typically serves chateau ste Michelle bottles that retail around $12, and occasionally serve Browne wines that retail $20+. Ive noticed the difference since I started the DL status challenge a few months ago.
Maybe that is the angle: point out that they are inferior to AS with wine selection. Based on recent history, DL does seem to care about beating AS. Could work...