If you have high bushel corn 150+ you will not want the air foil. Otherwise it works well for all other crops. Maybe there is a way to get it to work in corn, perhaps always returning to rotor, replacing wires in concave, blocking sections of concave, etc to make sure less material hits the sieve. Anyway, we didn't have good luck with it in corn, but I'd like to know if anyone has... it's kind of pain to swap it out two times a year.
We have it in one of our machines, although I haven't really noticed any distinct advantages over the standard sieve as far as loss goes. It's not bad but I don't think it's the best thing since sliced bread anyway. We have it because it came with the combine, we haven't run out and bought them for the other two machines yet!