Pat, I've never used a GPS system but I'm told that guidance on east-west passes is even worse. Just not enough satellites in the north to have accuracy going east to west. That's kinda become one of my two standard questions when talking with the "fresh out of sales meeting" reps.

1. Does the 4 inch accuracy hold when it's taking an hour to make a pass?
2. How does your system do if I'm seeding east to west?

Sales type with real world experience will acknowledge deficiencies in those areas. Others get a blank look, followed by the standard; "We haven't seen any problems." response.