Member "Runner" has quite a bit of experience with a 72" RFM on a 2520, and has moved to a mmm for stability, and traction on slopes. In a tractor, to be used day in, and day out I would look bigger, and heavier. I would start with a 4105 (3000#, and 65" wide w/ R-4 tires) The turning radius is a bit big though. Other than a specialized orchard tractor, or articulated tractor, I think you will need some weight, and width. The 3000 series seem narrow, and high for that application. Actually, I would look hard at a Kubota
L3240, and up with their wider turf tires. It is an impressivly stable looking set up to me.