We are looking at buying a tractor that already has a Trimble autopilot installed, but it is a Nav I controller. How much performance difference is there between a I and a II controller, and what would a 5 year old Nav I controller be worth? The autosteer system is not part of the tractor deal. We have to buy it from the previous owner and trying to decide to buy the older system that is on the tractor or just go with a new Nav II controller. Also the tractor currently has a Trimble 214 receiver that we could buy. I understand this receiver could actually be used as a base station. How does the 214 compare to a 252 receiver?

Thanks