We installed a AFX rotor in our 1680 last fall, also neighbour across the road has one in a 2188. We combined a heavy crop of wheat with lots of straw last fall, canola, edible beans, soybeans and corn. Neighbours also did rye and oats. We both found there was no more rumble noises, it feeds even and you can load the combine to a nice working level and it stays there. We turned up the HP some but could use more and still make a nice job. Viny crops fed great, the only thing was that we had a dry harvest so not sure as to damp straw but green soybeans didn't show any problems. As to the stewart rotor ears, I saw a set on a rotor the other day, the augur part is only the same diameter as the rotor barrel so is not like the IH rotor auger but maybe it still will work. I had a speacility rotor before with rice spikes on the back half but was still no good in tough vine crops or heavy swaths of damp straw. If you would like any more information E mail me. I live in Southern Manitoba, Canada.