I have a 9650 STS with the original smooth threshing elements on the rotor. With 1300 sep. hours, I am thinking of replacing them. Should I replace them with new smooth ones from Deere, or the rasp type element from Loewen? Deere parts told me that the Deere rasp style is only for a bullet rotor and they won't fit on 50 series. I like the idea of the rasp style better and am leaning that way. Any experience with changing out the original smooth style element to new ones? Which ones last longer Deere or Loewen?