Here is my mini review of Delta. Delta business was alright. I flew it in June to Joberg. The year before we flew Qatar business. It was fantastic in my opinion. Food was better, the qsuites are better, the staff helping you was way better, and it was a ton cheaper. That was during the covid chaos though and they were basically giving away those seats. Still now they are quite a bit cheaper. I saw that the dates I was looking at next year they are about 8k instead of the 11.5k that delta is charging.
I will be flying delta one next year though, but that is only because of the free upgrades. It's just too damn expensive. I also felt like the delta one walls were too short. It was not great privacy overall when people walked by. The Qatar suites I felt like had much higher walls so as people walked by, you'd usually not be bothered too much as you only saw the tops of their heads unless really tall. On my flight to Joberg, I had a window seat on Delta. This seat was set up where it's the seat close to the window and not offset away from the window. Basically it staggers left and right for each row. The armrest on the right next to the plane exterior was pure crap. It was so short and completely uncomfortable. I was baffled by the design. I changed my seat for the return flight, still a window seat but I made sure to get the seat that was offset away from the window this time. This setup is way better since the armrest towards the plane exterior is now also built into the area that is your shelf for drinks, etc. It wasn't a tiny little protruding armrest like before. I know I'm nitpicking but it seriously bothered me on that long of a flight.
Food going to Joberg was OK. I picked a lamb something or other and it was good. It was one of their special regional choices. The meal coming home was alright, nothing great but nothing bad either. Some type of chicken. Here is where I think Qatar is better by far. They basically have a dine at any time setup. You push the attendant button and ask for dinner, or breakfast, or whatever is on the menu. I don't know how often you could have had a meal but that was a great setup. I had a couple meals that easily could have been served in any fine dining setup and were fantastic.
If I had to pay for business class, I'd pick Qatar hands down. If you are kind of stuck like I am with delta because of miles and global upgrades, then go with whatever airline you can to get into business. It's still way better than coach.