The "harvesttrak" is a tool, and if used properly can be a huge advantage, particularly if your concerned about grain loss. But like all tools, it's only as good as the guy setting it up!! Whats the old saying, a poor tradesman blames his tools....... :} Set the combine up normally, get off your butt and see what is actually coming out of the back of the machine, when loss is acceptable set the sensetivity to suit the speed you are traveling at and hey presto, you should have a "guide" to the grain loss of your combine. As conditions change you should be able to speed up or slow down to, depending on what you deem as acceptable loss. If all of a sudden it starts reading really high loss for now real crop change, stop, get out and have a look at the combine, don't just turn the bloody thing down and keep going. Not that tricky really!! Now wonder JD's have earned the reputation of Green Airseeders when I see the number of guys who blindly turn the senitvity right down and just keep feeding it into her. She'll take it all right, no worries about that, but look at those ugly green strips that appear after the first rain after harvest.