I talked to a local JD dealer about this today. He recomended going with the non bullet style factory JD elements, over the bullet style and Lowen elements. They are also a dealer for Lowen, so I was somewhat surprised to hear this. I am new to rotaries, but I can't see how the bullet style elements would move the material out the back any quciker. The dealer did say the bullet style elements had a little more meat on them compared to the non bullet rotor elements.