Except ... professional farmers in real life who make a lot more money than most of us use ... GPS. I have Googled the proper uses of agricultural GPS systems and as part of immersion in the game I have used GPS in the same way they do in real life, which is the prevention of excessive overlap when manually harvesting or working fields.
Now, a player playing in third person - a.k.a. arcade - view ... for that player it is indeed easy to manually drive and not have any overlap at all. However I choose to use only first person view. i can't stand third person view. But in first person view I have the same issue real farmers have, which is overlap due to limited visibility and tracking on the edge of the headers/equipment in various situations.
Anyone can drive a straight line in a game. But GPS has, at least for me, never had anything at all to do with driving a straight line. It was all about efficiency in working the field with the least amount of overlap, as well as precision in maneuvering on rows and headlands.
