Yes, its really down to the basic physics of granule weight which essentially determines how far it can be "flung" against air flow...
I know that in the full size industry here in NZ the fertilizer companies are always striving to make more granulated products as it is very much less wasteful, safer in aerial application, and together with modern GPS mapping on board aircraft fixed wing and rotary, more accurate.
....But in the meantime...for simulation of the more normal ops I want DUST!!!