I have worked with the UD Plus, Ag Leader Insight, and the AFS Pro 600. In my opinion Insight is a very good aftermarket yeild setup. It has some mapping ability the the Pro 600 wont have until 2008. For a user friendly and data managment reasons I would rather have the Pro 600. The screens on the 600 are much easier to understand and look like something you should see on a 2007 machine.