We replaced our M2 with a 52 w_520 flex and 6R30 corn. Have had it for 3 full seasons now, wish we had made the move long before. Uses more fuel per hour but gets twice as much done. Get the cummins, very common and easy to get parts if needed and hold their value better. For us 4wd is a must and makes it turn better when loaded, the rear axles and assembly are heavier eliminating the broken spindles and inherent problems. If I had to do over, would spend a smigion more and went for a 62 with a 525 or 825 flex. A lot more machine for not much more and parts are more common by Agco and aftermarket.. On a good dry 10 hour day in 40 bushel beans we can clip off 70 acres, in corn our limit is what a couple single axle trucks will haul, as soon as you get back with an empty truck you get back in and cut another load.. Watch out, you will need bigger trucks.. Dont look back