I may be taking a new job shortly that will likely involve regular domestic and international travel from Austin (approx. 50% domestic, 25% Asia, 25% Europe). I'm 85% of the way to my lifetime million miles with AA and have been AA gold in the past but do not currently have any elite status. Since Austin is not a hub for any airlines, any recommendations/input on which of AA, DL, CO or UA I should try to concentrate my travel on when I have a choice would be appreciated. I use miles primarily for domestic and international economy travel (I've always had reasonably good luck with AA on getting award seats). Thanks.