I hear a lot of bad things about Delta and their so-called skypesos. I have been flying DL almost exclusively for about 4 years holding Diamond status for as long as it's existed. What I like about DL is... Almost always getting upgraded domestically Lounge access (including AF, KL, NZ lounges) My understanding is that AA doesn't offer automatic upgrades even to executive platinums (I'm already an AA platinum thanks to a status challenge this year). I'm 6'2" with a 50 inch chest, so not being crammed into a coach seat is my primary focus when it comes to status. Redemptions are nice, but I travel nearly constantly for work, so personal trips are few and far between. I travel mostly domestically but 2x/year each to Europe and Australia. Qantas is much more attractive as a partner than Virgin Australia, but on the other hand, AF/KL seem better than BA. Useful upgrade certificates are a big "grass is greener" item too so when I fly 14 hours LAX-SYD, I can have a bed. So, after that bit of ramble, here's my questions... What are the pros and cons of staying with DL/Skyteam vs AA/Oneworld? Am I correct about AA being less upgrade-y? (and/or are any of my other assumptions stated above false). I'd hate to trade four uncomfortable international trips per year for dozens of uncomfortable domestic trips. I've got some planned business travel to HKG, SIN, SYD, MEL, ADL, DEN (unfortunately, from a mileage perspective, all back to back) in Q1 2013, so the time to switch would be soon if I'm going to do it.