American can take you anywhere that CO can (and then some) and 600K would actually be usuable on AA.....I'm not talking "Easy Pass," but standard rewards are just about always available. Not the case with CO.

Domestic upgrades are the loss if you primarily fly domestic. AA simply doesn't do it and yes the fees have gone up. Some of us do actually pay Y or B fares so they're now given to all elite levels vs. the previous EXP only.

AA's highest level is 25k more than CO but those VIPOW's mean you'll never play the HoKeY game. Even if you don't attain that, you don't have to play it with mileage. Plan a little ahead and you should have no problem upgrading to Europe, South America or Asia with miles....much easier than CO, and, as previously mentioned, on any fare.

Not trying to "sell" you either way. Take a good look not only at your business travel patterns, but also what is important when it comes to redeeming and flying for vacation (which is about 1/2 the reason of why I fly so much for work!)