Thanks for the info.

At the end of the day all I care about is can AA reliably get me home when I want to go home.

UA was able to get me to Chicago this morning when AA was not.

AA was very reticent to switch me over to UA, telling me things like "every airline was affected by the weather, UA doesn't have availability either". I was only able to get switched over by telling them specific flights with availability. Thank you expertflyer!

Can't say I enjoyed my experience with UA (that is a tale for another day). I recognize I am a nobody to UA, but I really don't feel like having a ticket agent arguing with me at 5:30 in the morning when I am just trying to get a boarding pass.

For future AA flight cancelations, I'll probably immediately check availability on UA, and if seats are available insist that AA switch me over.