Case in point, I flew B6 JB mint back from SFO to BOS on Thursday? Friday? Last week (it all blurs). Although they had a nice written card and the food was good, but I had to signal about 3x each time to get a new Seltzer (and I was in the front bulkhead, not hard to see). And I drink 1 can of seltzer every 90 minutes on long hauls.

On this morning's DL flight, I was:

1. thanked for being PM as I boarded,
2. After being stuck in almost the worst seat on the flight (window in the row before exit, on a plane with about 3 empty seats) and striking up a convo with FA (honestly saying that I fly B6 for the legroom, Delta for everything else), I was discreetly passed a note that the middle exit directly behind me was available.
3. Three beverage services in economy (same distance from SFO to BOS, regardless which metal I'm on)
4. That same FA just handed me a small bag of chocolate as they were doing final cleanup (I had jokingly begged for the Augustin chocolate during the snack basket round).

These types of little things are why I fly Delta.

AA and UA used to with the Amex Platinum card but both cancelled it probably 10+ years ago and only DL remained.

Happened for me on the SEA-GEG flight. I flew Alaska one way and DL the other. Alaska flew a full 737 and drug out the carts to serve everyone on board in Y (although you had a choice between water and OJ in Y and in F it was full service) flew DL back on a CRJ 700 and the FA clearly stated "no services at all including requests I wont serve anything" (This message was for both Y and F)

Seemed amazing to me how the exact same route was handled by competing airlines.

This is probably related to DL & Amex's contract. I'm guessing that AA & UA saw the value of having a high fee premium card of their own, and there may be some exclusivity clause with Amex and DL.

I think they are. I'm second highest or top tier with AA, DL and UA and I do feel that Delta is different. It's hard to give concrete examples but one that stuck with me was at the ATL B SC a few weeks ago. There was a line to check in and an agent came around with a handheld scanner and was scanning BPs and Amex Plat cards as fast as possible but also taking the time to say "Mr. X Thank you for being a Y Medallion Member" to each person. I'm in plenty of Admirals and United Clubs too and I can't imagine that happening there.

Skyteam has Aerolineas Argentinas and GOL as partners, so Argentina and Brazil are well covered at least and they are the two largest countries in South America, plus AeroMexico in Mexico, so that covers a good chunk of Latin America.

I consistently think that I should stop being DL loyal and switch to a different carrier. AA is usually the front-runner since they have direct flights to where my parents live, I can fly BA direct to LHR, and soon I'll have a nonstop to HND. Every time I fly AA, however, I remember why I don't switch. The planes are always a mixed bag whereas DL has a pretty consistent hard product. The service is mediocre whereas I feel more at home on DL (could just be a familiarity thing). The 500-mile upgrade thing for AA Gold is wonky at best. I may not have had a lot of success with upgrades as FO but at least I didn't have to earn or buy certificates for it.

At the end of the day there are things that DL does well that AA doesn't. There are things that AA does well that DL may not. There are great employees and maybe not so great employees at both. I personally like the way DL treats me over AA, so I guess that's what makes them different.

Given I have only AS status, I flew Delta recently when AS wouldn't get me there (which is basically anywhere east of the country, or east going east).

I find it amazing Delta has such a hodgepodge of airplanes and yet seems to still have them decent (maintained well). Isn't it supposed to be when planes are standardized things are much easier? Like all Boeing?

I find their pilots are very visible (on the few flights they are either in the galley as you exit, saying goodbye, or standing at the door of the cockpit). That is an important bit, as it is basically your last memory of the flight, and can turn a neutral experience into a positive (with a face to attach to the flight).

Their flight attendants don't seem as grumpy, and do seem more caring.

And I also trust them more in terms of actually getting you there, even with a connection.

So I flew Delta from MIA, which is no easy feat (given it is AA's hub).

Quality-wise? Probably, although KE is really good (and I'm writing this from a KE lounge, of all places). But network-wise? Definitely not.

That said, as someone who regularly flies MU, they're not as bad as you think they are. They're the airline that allows me to maintain status, after all, and I wouldn't be flying them as much as I do if they were that awful. Then again, it helps to have low expectations of Chinese airlines.