I have heard good things out of the "M" series JDs, I have the 4320 (48hp), I think for its size it's over powered, I couldn't imagine 66hp in that frame lol.
That being said I have a family farm (other side of the fam) and they run everything case, they have tractors from the 1970s all the way up to a 350hp magnum they bought a few years ago, that part of the fam swears by case, but the case today isn't the case international they used to be, idk if there any better or not, CNH.
I drove a 110hp 6 series "M" a few times loading up bales of hay I was buying off a farmer down the road, it had the auto leveling bucket and was a sweet ride, can't say about reliability on that.
I haven't had any problems to speak of on my 4320 so far but I really like the ergonomics of the tractor, it makes it much more of a joy to drive, not sure how the case is laid out.
I will say this though, I rarely ever hear horror stories on here about case but seems people are always being let down by JD.
If I had that much bad luck with a company I would switch to another.
If Deere is offering you a incentive to upgrade and you could recoup more of your money by doing so I would take that deal, up grade and trade off the new tractor instead of a broken one.
