Economy Comfort and Comfort+ are anything but comfortable. One is a sow's ear and the other is a sow's ear soaked in Woodford.
I had to edit this because I skipped over your last paragraph. You think Delta's F or J is the finest in food, beverage and service? Do you pay for your own flights? If so, I suggest you start flying private. I'm just a peon where I work but my company has a whole fleet of aircraft just for our executive management. We also employ (as in on the payroll, not contract employees) private pilots and FAs to cater to them. I've met some of them and from what they have told me about the experience, Delta's J product is a cattle call.