Food: It will be a toss-up. I would say that AS is more consistent and is generally decent, though not amazing. DL can be good or terrible.

Wine: As serves Ste Chapelle Winery Red Blend. DL offers Imagery Estate Winery cabernet sauvignon. They are both in the $10.00 bottle range which is cheap and not first-class in my book, though from a quick search, it seems like Imagery is better reviewed.

Seats: IMO Delta clearly wins on seats. They have seat-back screens on all flights and I think slightly better recline.

Personally, I would fly DL because of my medallion status and because they have better ground customer service and more slack in their system to fix things when there are problems like bad weather. The food and wine will be mediocre on both.