Originally Posted by
Microwave
A further clarification: AA do not fly 757s with 22 or 24 seats across the Atlantic–not even in a substitution situation–so no worries there. The configuration with 16 seats has "wedgie flat" seats (the seats are flat, but not parallel to the floor) while the configuration with 12 seats has recliners. Personally I'd avoid all 757s across the pond if possible, though the one with 16 business class seats is the best of the bad options.
But they have been known to use those domestic 757s on the LIM-MIA route, which is what the OP is flying.