The whole exchange here amuses me. Most people commenting herein fly either UA or AA but rarely both with any frequency--so their opinions IMO are nothing more than defensive posturing to feel better about their choices/experiences.\

I fly UA more but I fly AA often enough. I rarely fly DL. I live in SoCal and most often fly from SNA but sometimes from LAX when necessary. I fly both domestically (mostly for work, sometimes leisure) and internationally (mostly for leisure, sometimes for work).

I see UA and AA F domestically as being very comparable. AA has an edge on a few routes where they fly a widebody (LAX-MIA is a great example), but other than those particular routes which are few and far between, the AA and UA F experience in the USA is pretty comparable. UA has an edge on seat quality and food, largely because AA often gives you pmUS equipment that is absolutely HORRIBLE. Both UA and AA can be decent, good, or horrible with service--it depends. But both are average to decent.

Internationally, UA GF is better by a bit than AA F. AA has newer F seats on its new 773ER flights, but the truth is that they are no more comfortable than the older UA GF seats. In fact, I generally prefer the UA GF seats over those newer AA F seats. I find them more spacious, more comfortable for sitting, much more comfortable for sleeping, and more common sensically laid out. The older AA F seats are much worse than UA GF. I also prefer UA BF over AA J. There is a bit more legroom capacity on UA BF compared to that on AA J. UA also has a far better route map, especially from the West Coast, too. Food and service internationally gives a slight edge to UA, too, in my experience, though I've had standouts on both airlines--and average to good service on both.

UA just seems to have more F where I tend to fly abroad. AA doesn't always have a competing F as it quickly reduces its F options internationally. UA wins hands down on route map and the availability of F overall.

For awards, UA GF awards are not that hard to get--though it is much harder to find them at the saver level than it was just a few yrs ago. But it's as tough to find a saver UA F award as it is to find ANY AA F award--especially on nonstop service internationally. Domestically, they are comparable.

AA awards cost less than UA, so that edge goes to AA--except that it's almost impossible to find awards at the reduced levels on AA. I can always at least get an award flight in F on UA when I want one, even if I have to pay standard miles to get it. On AA, I almost never find the award in F, especially if it's nonstop.

Overall, UA GF wins for me. I fly whichever one gets me to where I'm going most directly, of course, so sometimes that puts me on AA metal. But whenever there is a choice between UA and AA, I almost always choose UA.

I suspect my conclusion isn't going to be precisely the same for those flying from the NYC or ORD or IAH/DFW or IAD/MIA hub locations on the Eastern side of the country. But I live on the West Coast, and my West Coast experience is that UA F is better than AA F overall.