I farm for a living, have mostly John Deere equipment. I have JD because my dad had it and the local dealer is 11 miles away, nearest Case IH dealers is 30, Agco 25, I wouldn’t run Agco for free.
Most of my equipment is preemission but a lot is computer controlled. I can a lot to my machines but there are something’s computer related that I can not. A lot of these problems are dealer related, your service manager can be a good guy or a dick, and it’s not just JD, Case IH is the same deal. Semi tractors and all kinds of other stuff are having these same issues.
I had 2 semi tractors that gave me fits so I sold them and now have all mechanical trucks. The problem with farm equipment is the newer, larger equipment gets more done, but that does come with dollar signs and being more attached to your dealer, warranty is your new master, the machine goes out of warranty and you have to go to the dealer on some of it.
Roughly 1995 Deere started using more computer controlled equipment, most of this was good but yes it does have its quirks. So much for the larger stuff. I had a neighbor that farmed and had a small feedlot, 25 years ago he bought a Belarus tractor for his feed wagon, it was half the price of a comparable JD, 4 or 5 years later he had a JD, the foreign one had no support and was always laid up. Lots of Kubota small tractors around now but I don’t have any personal experience with them. Older clean equipment is really bringing good money now because of the older guys like me still like to fix their own equipment, good luck on your purchase!