Observers in politics say, "don't listen to what a politician says, but look at what he does." That's the real measure of what he believes and what he will do in the future.
It's somewhat the same in the corn field. The proof of how the field was planted and how the planter worked is in the crop that grows in the field. For example, we recently visited a field where there was very little overlap into the end rows with extra corn from the field pass. Planting stopped either exactly at the first end row nearest to the body of the field, or in some cases extended a couple rows in.
You can immediately know one of two things happened. Either the operator planting corn was darn good and hit the mark nearly every time, or the planter is equipped with row shut-offs and a computer-based GPS system that senses where corn is already planted and doesn't allow the units to plant where there is already seed in the ground.
Many farmers are reporting that row shut-offs may be one of the fastest paybacks in precision farming, perhaps right behind auto-boom shut-offs for sprayers. Greg Helich of the University of Kentucky calculated recently that payback for both is so high that it makes sense in almost every case to invest in the capacity to do both row shut-off on the planter and auto-boom shut-off on the sprayer.
In the case of the planter, you not only save seed but also avoid over planting on end rows. Since we don't yet have hybrids that can handle 60 to 70,000 plants per acre very well, it typically means higher yields on the end rows if you can somehow keep from planting extra kernels there. That's one of the quick paybacks for row shut-off technology.