AA is very smart! They've taken others mediocre ideas and designs, and transformed them into industry standards.
Sure, UA decided to give a few of their passengers "more room" in coach, while AA decided to give all of their passengers "more room throughout coach," and "throughout business."
Yes, UA followed the lead of other International air carriers, in offering "Suites" in First Class, while AA took this same idea and revolutionized it.
UA started updating their a/c seats a few years ago, while AA is nearing the completion of their refurbishment efforts, in nearly a 12 month period.
All in all, its the passenger that's noticing the premier difference between AA and UA, and that's all that matters!
We are the people of American Airlines. And we know why you fly.