I don't normally go the spreading. My observations are that the application rate depends very much on the atmospheric conditions which affect how the product flows out of the hopper. I obviously has various settings, but what put on 200kg/ha yesterday might not to today. I have had it to within a couple of kgs/ha, but you don't know what it puts on until it's put it on. As far as spread pattern goes, it always seems as good as any. The veins on the discs wear but only take a few minutes to replace.