Hello Bob, I'd be happy to explain Deere's theory of economics concerning thier combine production in the North American market, as explained to me when I took a plant tour last year. At THAT time, rotary vs. conventional production was roughly 19 to 1, meaning that the plant was producing 19 rotaries for every conventional being built. The day I was there, only 2 conventionals were anywhere on the line, and our tour guide explained that, at different phases of production, the line had to be stopped for "fixture changes" from rotary to conventional production, then back to rotary. Even at that time, our guide was "hinting" that Deere was "in the works" to eliminating this problem, although he didn't go into any great detail. He did state, however, that producing both technologies simultaneously impeded production. I'm not doubting that far, far more rotaries are being sold than conventionals, nor am I disputing that the STS's have greater capacity in almost All crops (not just corn),nor am I disputing that there's a lot of corn being grown throughout the United States. I'm merely stating combine design and production does NOT entirely revolve around corn. Western Canada is predominently wheat and other cereals, while in my region (southwestern Ontario) we have an even mix. STS's seem to "shine" in most crops, NOT JUST CORN!