I have done CM out of PTY and AA out of DFW. The principal advantage of CM is that you can get an EUA, if available, out of PTY to SCL and back. No copay is required on this trip as opposed to CO BF flights to Brazil, which do require a copay. There used to be a glitch in the CM and CO software which held up EUA's on CM if you had a ticket issued on CO. This problem has been cleared up.

DFW SCL is 2 cabin J and Y and CM is also two cabin, very similar to domestic F and Y.

Food on CM is better than domestic F, but not as good as BF. Seats are standard F seats. The prior posters comments are correct, the arrival and departure times for CM in the maldrugada between 2 and 5 am depending on daylight savings time observance in the US and Chile. For me this is not conducive to rest on the 6 hour return flight from SCL or for getting some sleep upon arrival in SCL.

CM service is good, but I have no complaints about the service to Chile on AA.

AA's seats in J have regular legs rests and are more conducive to sleep than the CM seats in F. You will not get a free upgrade to J on AA, you must use miles or buy the ticket, or if you have them, use VIPOW's. AA's departure time between 9:30 and 11:30 pm out of SCL is far more conducive to sleep than the CM departure time.

Another factor to keep in mind is if you are traveling to SCL during their winter, May to September. SCL fogs in frequently at night during their winter and on more than one occasion I have either stayed over in PTY or have seen flights diverted to Mendoza. If SCL fogs in, CM must wait until the plane from PTY arrives because CM has but one aircraft available. My impression is that the early morning 6 amish arrival for AA as well as the departure in the late evening make AA somewhat less subject foggy conditions in SCL.

While in the four years that I have been flying to SCL, I have done CM fare more than AA, I am pretty much decided to go to AA in the future. As soon as I reach EXP on AA later this month, my future flights to SCL will be on AA, for which I will use VIPOW's. My main reason is that the arrival and departure in the middle of the night cab be avoided on AA. In addition, the seats are more conducive to sleep on the return flight to DFW, rather than the CM seats, and the nearly 10 hour flight, with only one more connection home rather than two with CM and CO drive my decision. Granted, upgrades are not certain, but that is true in both cases, if CM sells out its inventory, you will not get an upgrade on EUA. The full Y fares rule on CO also applies to CM, but full Y fares are really expensive on this route.

Depending on your budget, I would get the B fare to SCL, rather than the full Y, B fares run about 2K, as opposed to the 4 to 5K for full Y. The main advantage to the B fare on AA is that it is treated as full fare for mileage upgrades. B fares upgrade for 10K miles each way without copay. Lower discounted fares require 25K miles, PLUS $250 copay each way. If your budget puts you in the position of not purchasing B fares and being unable or unwilling to pay the copay, the CO and CM are the way to go.

CM is used frequently by Chileans seeking a cheap fare to the Carribean for honeymoons and other pleasure trips, so the flights are often quite full.

Hope that this helps.