With the new year rolling around soon, I am trying to decide which airline is going to be my sole airline next year. I will be traveling domestically 1 to 2 trips per month. From where I live in South Dakota Delta, American, United, and Frontier are the main airlines that fly out from here. I have been loyal to AAdvantage in the past but I am considering Delta for next year. When it comes to an airline loyalty program, there are a couple things I look for: ability to earn and redeem miles and also the ability to get upgraded from coach (my company only pays for coach). A plus for American seems to be that their miles are easier to redeem however I must take a 2 hour flight in a CRJ to either ORD or DFW to catch my connecting flights, whereas Delta only involves a 30 minute CRJ flight to MSP to catch a connection but from what I hear is harder to redeem miles at the lowest award levels. Anyone have any thoughts as to any pro's or con's to each program for my situation? Thanks guys and gals!