One important thing to keep in mind is that you had the 12-row in corn, where most combines, no matter what size of head is on it, are over powered simply because corn doesn't take the amount of horsepower soybeans or wheat would. It threshes easily and very little material (ideally, anyway) is running through the machine. Really, the clean grain elevator is about the only thing that works harder in corn. So it doesn't surprise me that a 2188 would handle a 12-row in corn. Rotors take more power, yes. But "more power" in corn means something different than in most crops.