Mine uses an aftermarket compressor, Bracketry, Hoses, Condensor, and Evaporator. The evaporator box is right behind the glovebox, all the ducting ties into the OEM ducting for dash vents.
In theory the aftermarket A/C system SHOULD out perform the factory a/c system simply because the evaporator is located INSIDE the cab NOT under the hood in the engine compartment.
A/c is simply heat exchanging, which means when the evaporator collects the engine compartment heat aswell as the cabs heat, when in MAX position.
I was told the system was operational when i bought the truck, but all i can verify is that it had pressure, and the compressor does turn. I blocked off all the connections to keep dirt out of everything when I removed it.