Run from AFS as fast as you can.  As AFS PRO has posted above, AFS is not compatible with anything but red paint and they are not even trying to be compatible. They use some Trimble components, but use their own firmware so that Trimble  can not even plug and play with them in every situation.  AFS will not cooperate with third party software developers in any fashion.  They will not provide their file specs or reply to any request for technical assistance in reading those files.  I am a former AFS user and will freely admit that AFS has had some good hardware.  But we need open architecture in the precision Ag industry and AFS is making no effort in any way to support open architecture.  They are dead last in support of open architecture.  The only way we are going to influence them to change this attitude is to speak with our pocket book.  We need to refuse to buy from companies that do not support open architecture.

In his post above AFS PRO stated that you "might" be able to log with the 600 pro in your John Deere tractor.  That may or may not be true.  I can not confirm or deny that.  But if you can log with the 600 pro, you will not be able to read that log with anything but the AFS software.  You will not be able to use those logs in any of the better third party software that is on the market.  I am not sure if outside vendors can write prescription maps for the 600 pro or not.  If they can, they have developed this capability without any help from AFS.

If you want to look at steering systems that are compatible across different vendor's platforms, I would suggest that you give strong consideration to Trimble or AutoFarm.  Even John Deere has support for other manufacturers platforms.  If you are wanting to move the terminal between tractors and a combine for yield monitoring, the Trimble autopilot using the AgLeader Insight for control will be your best bet.  The Insight is currently the only third party platform that does both yield monitoring and steering control.