Does anyone have any experience with GPS systems for small tractors? I'm not talking about one that will steer my tractor, I just want one that will give me good precision display to follow for parallel rows.

A made some disc row markers for my two row planter this year and it's hard to express how much easier it made cultivating and spraying with parallel rows. I noticed a GPS unit on a small tractor on a Marketplace ad and it dawned on me that there might be a better way than row markers. The tire tracks I had to follow putting down fertilizer this weekend were laughable.

Anybody got one they like?