We run the Vittetoe with dual spinners. However, since we put the FFS air deflector in, I'm not sure we even need the chaff spreader. I tried to tell last year in wheat, riding behind the machine in another combine, but there was so much material coming out the back of the machine I couldn't see if anything was hitting the chaff spreader or not. I should have stopped, turned off the chaff spreader, and compared the spread of material, but when it's 100F and you want to get done with harvest, it's hard to justify stopping for experiments. Maybe some of the guys with the deflector can chime in.