Don't want to start an argument, but I guess I need to point out the differences between rotors. The advantage of either rotor is that slower rotor speeds are possible without increased HP requirement, since the mount_rotor bar arrangement prevent material from escaping to the cylinder center -- holding the crop against the concave, helicals and cage surface. Also, it's pretty much understood that the faster the rotor speed, the more chance for grain damage, whitecapping problems and that trash will be torn up worse and that more cobs will be broken up. Main differences are in bar mounting -- we mount bars flatly so the leading edges of thte teeth and the top arch of the bar are effectively used. The CDF has the bars sloped forward. Difference in feeding is that the leading edges of the teeth on the flatly mounted bars engage the crop much more effectively than the rear of the teeth on the sloped bars. The sloped bars pinch the material while the flat mounted bars impart more of a tumbling action and trash doesn't need to be torn up as much for separation. Other main difference is that we use a 20" diameter tube while CDF uses a 18" tube. Our rotor maintains material at a 1" closer spacing to other components than CDF -- in addition to the sweep agitators which we use, I think that's why grate adjustment isn't as critical with our rotors. Also, with a 2" larger tube diameter, centrifugal force will always be greater at any given rotor speed. There's more to this, but these are probably the main points. Hope it's clear. Terry Welch