Thanks and sorry for the lack of information.
It is AA on both flights. When I looked at the information my assistant gave me, it was Airbus 318. It would be business class on either flight.
Price is largely comparable. The elapsed time was shorter for BOS-MIA-BOG than for BOS-DFW-BOG, but to Sao Paulo, IIRC, the plane out of DFW was much nicer than the plane out of Miami.
I'm Plat for Life on AA but have been BA Gold for at least ten consecutive years and am shooting for Gold Guest List on BA this year.