Originally Posted by omegadeal

I was a UA 1K for a number of years and just switched to US/AA at the beginning of this year, and quickly made CP on US through the trial preferred.

Here are the pros/cons of US/AA over UA

Pros:

• Upgrades seem to be slightly better on US than they were on UA for me. This may be due to the fact that UA has a Global Services tier above their standard 100k tier which is invite only and gets upgrade priority
• One of the reasons I left was the requirement to purchase a higher fare class when using GPUs even when the upgrade wasn't available (aka the upgrade lottery). With that being said, UA gave 6 GPUs per year while US only gives two
• Oneworld has the only direct flight to Europe from PHX (PHX->LHR on BA). I'll end up using this one a good bit

Cons:

• I'll also miss the ability to move the flight forward or backward 24 hours using only the mobile app. There are many times I would fly home the night prior than originally scheduled because I was able to get my work done earlier.
• UA award redemption seemed to be much better for international premium cabins, but I must admit that I am new to US/AA. It looks like there are very few saver awards on US.
• The UA website seemed to have more functionality. There were very few things I couldn't do on the website, and rarely had to call in. On US it seems like they want you to actually call in (i.e. no way to check upgrade availability, no waitlist (i.e. just keep calling back)