Don't go with the Green Star. You'll wish you hadn't! The Green Star monitor is not nearly as accurate because it doesn't base it's values on a curve, instead a straight line. It assumes that your ground speed and everything else remains the same which you and i both know it doesn't. Well, if you have questions, you should ask an ag leader dealer. They will help you more. I tell you what, it is kinda complicated what they'll explain to you, but when they do it'll make perfect sense if you stop and think about it.