Depend's on how the rotor and concave is set.Straw will look the same as a conventional if you take out all of the knives ,close the concave all the way,and run the rotor over 850rpm's.A little leary myself about all the knives had 9 left in once work's good.Found out the hard way that you can't run only 9 knives in soybean's and tore up top plate by plugging often.Dealer at the time knew as much about the combine as the man on the moon.Every combine left there with only 9knives in it.After a couple of top plates our's and a few other's thy now leave with 21.If you can get in touch with the guy they send out from agco to set up new machines with dealer's he know's it all.Started with 8560's and I saw him working on a 9680 this fall.He know's the massey rotories the best of anyone.