If there were not the substantial chance of the company's failure, my choice would be US hands down. I detest O'Hare and with AA having closed its hub at BNA, I will need to change at ORD for my destinations in the lower Midwest.
Even tho it will never equal AA's Miami hub, US is beefing up its service where I need it, FLL and LGA, and also gives me nonstops from NY (albeit RJs) to Midwest destinations. And on top of that, I can start with comped GP status on US without any of the challenges nonsense.
So even tho the auditions do not start on equal ground, the spectre of financial failure and the possibility of continuing deteriorating service on US keeps AA in the picture for me. There is hardly much doubt that if US takes the pipe, the LGA Shuttle service will end up in the hands of AA, and they will have gained the twice monthly DCA full fare that I now pay to DL.