I understand your feelings, as I shifted my business to AA when UA really started $h!tting the bed after the merger. Ironically, I've continued to maintain 1K status, just by circumstance.

What I can say is that the PQD requirement on UA is more difficult to deal with than the upcoming EQD requirement on AA, as AA will use a formula to determine EQD for flying on OAL partner tickets and UA still forces people to 016 or UA metal. That alone makes the AA program more attractive, as you can keep your mileage earning up.

Differences to expect:

1) AA, now that they fixed things, tends to have better food.

2) AA's Wi-Fi product is more consistent. UA has at least 3 different products, and different ways they are applied. AA has 2 products, with even application.

3) UA is much better at dealing with IRROPS, even with the downgrade in that handling after the merger, unless you are an EXP. 1K to EXP is about even, though UA probably still has an edge.

4) UA's lounge access rules are better, but AA's lounges are better generally. UA has more food now, however.

5) AA generally has much better seating onboard, across the board. Some mild exceptions apply, but the general rule holds.

6) LAA FAs and sUA FAs are the best and are about equal. LUS East and LUS West FAs are much better than sCO FAs, with the exception of some international base FAs out of EWR.

7) Recognition as an EXP is generally better than as a 1K. FAs and GAs tend to be much more willing to take care of an EXP than a 1K.