Originally Posted by
j2simpso
.... To summarize : AA is likely the better option if you prefer upgrades over direct flights and on-time performance. ....
While not disagreeing with the first part, I think the on-time data disagrees with the second part.
Based on the most recent BTS report
(April 2018 -- issued June 2018), Mainline AA's 12 month trailing on-time arrival is 80.9% and UA's is 83.2%. AA has consistent been behind UA and sometimes behind WN (78.7%). HA (88.5%), DL (86.4%) and AS (84.7%) have been the leaders. Individual airports and routes may vary.