I can't see getting another Emerald just for lounge access in the US. I'd rather have the 100,000 or so miles that I'd get from AA as bonus miles than save the $250 for that year.
I've considered switching to another oneworld partner (BA or CX would be the choices that make sense) entirely, but I just shudder at the higher bar to getting to emerald the first time since I currrently only get about 125,000-150,000 q points a year in the AA system.
If BA had the equivalent of an AAnytime award I'd seriously consider it, though.
Steve